reddish colour and quite viscous. The gall bladder and bile duct appeared to be inflamed. The infected fishes were taken by trawlers working out of Wellington in August and October.

Trophic Stages. The trophozortes, immobile when studied, are rounded to irregular in shape, and vary from about 2μ to about 15μ in diameter. While there is very little visible distinction between endoplasm and ectoplasm, the occurrence of the inclusions in an internal position suggests that some differentiation exists. The ground-plasm is extremely transparent, and presents no visible structure. In living trophozoites a few tiny, irregular, granular inclusions may be seen, which are selectively stained by dilute neutral red. These inclusions are found in all but the smallest of the trophozoites. They are not seen in permanent slides. Trophozoites from about 5μ up usually have a few to many larger spherical inclusions. They are somewhat refractive, and are lightly stained by dilute neutral red. They average about 1 to 1.5μ in diameter. They are persistent in stained preparations.

The trophozoites have a tendency to aggregate which increses with incresing maturity. The clumped tropozoites fuse together to such an extent that the individual boundaries are completely lost to view. Masses of sporulating trophozoites occur, containing large numbers of developing spores, and densely packed with the spherical inclusions. Isolated trophozoites containing spores are also common. In the majority of cases each isolated trophozoite contains two developing spores, but about 20–25% of the trophozoites are monosporous (Figs. 2, 3). A single residual nucleus remains after spore formation is complete.

The many small individuals are apparently formed as a result of exogenous budding. Small trophozoites are multinucleate, usually with a minimum of two nuclei. Nuclear divisions begin early. After from three to five nucler are present (Fig. 2), the trophozortes enter a growth period during which there are relatively few nuclear divisions until spore formation is begun. Trophozoites which are to undergo budding, on the other hand, tend to exhibit a nuclear increase during the growth period.

Spore Dimensions. Based on spores from two Thyrsites. Breadth, 9.6–14.2μ (11.8μ); height, 5.0–7.9μ (5.8μ), thickness, 5.4–5.9μ (5.5μ); valvular axes, 4.8–7.8μ (6.4μ) and 4.8–6.8μ (5.7μ), capsules 2.4–3.4μ (2.7μ) by 2.0–3.4μ (2.4μ) Anterior angle, 71–128° (109°); posterior angle, 154–225° (199°); tangential angle, 145–180° (178°). Curvature index, 52°., taper index, 21°; valvular index, 90°. Breadth; height ratio for quartiles of breadth range, 1.67, 1.99, 2.24 and 2.37.

Spore Morphology. The stubby spores are in the form of flattened ellipsoids, with large, conspicuous polar capsules. In sutural view the anterior margin is convex, without interruption at the suture, while the posterior margin varies from convex to slightly concave, with a few spores showing a definite curvature (Figs. 4, 6–7) The two equal or sub-equal valves are similar in shape, meeting in a prominent, elevated suture, usually quite straight, but slightly oblique in a few spores. In capsular view the spore is essentially straight, although one margin may be somewhat more convex than the other (Fig. 5) The spore is slightly flattened, the thickness averaging a little less than the height.

The large, broadly oval polar capsules are placed near the anterior margin. They converge somewhat on the suture, and in a few spores are strongly convergent. They are opaque, the filament being invisible in fresh spores. The filament measures up to 35μ in length when extruded. The capsulogenous nuclei are usually persistent, and can be seen in fresh spores. In capsular view the capsules appear to be slightly rotated toward the lateral margins.

The sporoplasm fills the spore cavity in fresh spores. It is quite transparent, and extends upward between the capsules. A small number of rather large refractive spherules are usually present in fresh spores. These are sometimes in the sporoplasm, but are usually just outside of it, between the sporoplasm and the spore membrane. These spherules disappear in permanent preparations. There are two small, vesicular nuclei of variable position.

In a number of the spores the terminal portion of the valves appear to be somewhat thickened, in the region where the valvular nuclei appear during development. This thickened region does not appear in stained preparations, so presumably is persistent after the complete disappearance of the nucleus itself.

About 5% of the spore population has a triad form, with three valves and three polar capsules. The valves meet in three sutures, which pass between the capsules and meet at the apex of the spore (Fig. 8). Unlike the triad spores seen in some Ceratomyxa, these are very well formed, with quite normally formed valves. Tetrad spores were not seen.

Spore Variability. Although this species shows about the same kind of variability as that seen in strains of C. inconstans, there tends to be a somewhat stronger central tendency with relatively fewer examples near the extremes of the range. The position of the suture with reference to the valvular tips is quite variable, as indicated by the range of the posterior angle (154–225°), and is accompanied by considerable fluctuation in spore curvature However, 60% of the spores from one Thyrsites atun had posterior angles between 203° and 218°,

while 60% from the other Thyrsites had posterior angles between 190° and 214°. In the great majority of cases, the valvular tips are anterior to the posterior end of the suture, and the posterior margin is flattened.

Since but a small sample of spores were measured in one of the Thyrsites and the Jordanidia, no careful analysis of the similarities and differences of spore populations in the different hosts is possible. The small sample from Thyrsites, in all linear and angular measurements, had means which differed more from the full sample from Thyrsites than the small sample from Jordanidia. About the same range of spore shapes was observed in all three hosts. The maximal difference between samples was 1.0μ in spore breadth, with all other linear dimensions agreeing within a range of.0.5μ The means of the angular measurements were also very close, the greatest difference in anterior angles being 9°, in posterior angles, 2°, and in tangential angle, 2°.

Discussion. The typical form of the spore is such that it falls into groups I-A-1 or I-B-1. It is evident that the only species in these groups which it bears a close resemblance to is C. inconstans and C. gracilis. That it is closely allied to C. inconstans is suggested by its occurrence in a host of the general mackerel type, as well as its small size. The more rounded spore shape places it nearer to the border line between the Leptotheca and Ceratomyxa than the strains of C. inconstans found in New Zealand material. It is considerably smaller than the strain of C. inconstans originally described by Jameson (1929), in which fixed spores varied between 11.2μ and 13.33μ in breadth. The polar capsules, not measured by Jameson, are considerably larger than those found in strains of C. inconstans obtained from New Zealand fishes. Jameson describes C. gracilis spores as oval, with no distinction between anterior and posterior margins. It is evident that the form found in Thyrsites and Jordanidia cannot be C. gracilis.

Members of the Gempyllidae have not previously been found to harbour Ceratomyxidae. In the present study Leptotheca annulata has also been found in the same host species, and host organ. The conspicuous suture of L. annulata makes it easy to distinguish from C. minuta. Since it cannot be equated with any of the previously described species, the name C. minuta n. sp., has been proposed for it.

Ceratomyxa inconstans Jameson (Text-Figs. 2–3, Figs. 9–29)

Habitat. There are a number of strains of small-spored Ceratomyxa which appear to be best referred together to the species C. inconstans, despite differences in their spore from. They have been found in Scomber japonica, Usacaranx lutescens (Richardson), Trachurus novae-zelandiae Richardson, and Helicolenus percoides (Richardson). While not common, they are not particularly rare, insofar as is known. Unfortunately, not a long series of the mackerel group were available for examination, so repeated examples of each strain were not obtained. They were taken at various times during winter, spring and summer from hosts which had been taken by trawlers working out of Wellington. They did not occur in four Helicolenus taken at about 200 fathoms from Cape Palliser. The gall bladders of the Usacaranx and Trachurus were red and looked to be irritated, but there was no signs of abnormality in the remaining hosts.

Trophic Stages. In most of the fishes, the trophozoites were deteriorating when the gall bladder was examined. No trophozoites were seen in Scomber. In Trachurus the disintegrating trophozoites are rounded to irregular, with disporous forms containing nearly mature spores measuring about 15μ to 20μ in diameter. The rounded trophozoites found in Helicolenus are from 15 to 30μ in diameter, and include both disporous and monosporous forms. In Usacaranx the trophozoites are similar to those found in Trachurus, and measure about 16 to 18μ in diameter when carrying nearly mature spores (Fig. 9). In all cases the protoplasm is transparent, and carries a number of tiny, refractive spherules measuring from about 0.5 to 1μ in diameter. These inclusions are less conspicuous than the ones seen in C. minuta, and are missing in fixed and stained forms. In Helicolenus there are many trophozoites which are very small, averaging about 4–5μ, and apparently arising from the larger trophozoites by budding.

Spore Dimensions. From Scomber japonica. Based on spores fixed in sublimate-acetic and examined in water suspension. Breadth, 8.8–12.2μ (10.2μ); height, 3.4–5.4μ (4.4μ); thickness 3.4–5.0μ (4.5μ) valvular axes. 5.0–6.8μ (5.4μ) and 3.9–5.9μ (4.9μ), capsules,

1.0–2.0 (1.7μ). Anterior angle, 112–140° (125°); posterior angle, 195–276° (228°), tangential angle, 163–180° (178°). Curvature index, 7°; taper index, 50°; valvular index, 103°; Breadth height ratios for quartiles of breadth range, 2.00, 2.34, 2.50 and 2.58.

From Usacaranx lutescens. Breadth, 10.7–15.7μ (12.5μ); height, 4.5–6.8μ (5.5μ), thickness, 4.6–5.6μ (5.1μ); valvular axes, 5.6–9.0μ (6.8μ) and 5.6–7.9μ (6.4μ); capsules, 1.7–2.3μ (2.1μ). Anterior angle, 84–132° (105°);, posterior angle, 160–213° (191°); tangential angle, 130–180° (160°). Curvature index, 64°; taper index, 31°; valvular index, 86°. Breadth: height ratios for quartiles of breadth range, 1.91, 2.13, 2.45 and 2.72.

From Helicolenus percoides. Breadth, 8.6–15.4μ (12.0μ); height, 4.3–6.5μ (5.4μ); valvular axes, 5.4–8.6μ (6.4μ) and 4.8–7.6μ (5.9μ); capsules, 1.6–2.2μ (1.9μ). Anterior angle, 93–149° (109°); posterior angle, 168–228° (192°); tangential angle, 139–180° (160°). Curvature index, 59°; taper index, 32°; valvular index, 83°. Breadth: height ratios for quartiles of breadth range, 1.93, 2.07, 2.36 and 2.66.

From Trachurus novae-zelandiae. Breadth, 9.8–14.1μ (11.8μ); height, 4.5–6.8μ (5.5μ); thickness, 4.5–5.6μ (4.8μ); valvular axes, 5.1–8.5μ (6.5μ) and 5.1–7.3μ (6.1μ); capsules, 1.4–2.0μ (1.7μ). Anterior angle, 71–119° (98°); posterior angle, 150–210° (181°); tangential angle, 117–180° (162°). Curvature index, 81°; taper index, 19°; valvular index, 83°. Breadth. height ratios for quartiles of breadth range, 1.94, 2.12, 2.24 and 2.19.

Spore Morphology. The small spores are variable in curvature, and have short, subequal to unequal valves, terminating in rounded tips. In sutural view the anterior margin is always somewhat convex, although a few spores are seen in material from Scomber with the anterior margin nearly flat, and the axes of the valves angled somewhat forward (Fig. 21), and the material in Trachurus included some quite arcuate spores with correspondingly more convex anterior margins (Fig. 25). In all cases, the anterior margin curves smoothly over the suture. The posterior margin varies from convex to very concave. As indicated by the figures quoted in the dimensions section, the range of variability of the strains is somewhat different in the different hosts. In Scomber the posterior margin varies from extremely convex to at the most gently concave (Figs. 21 and 22), with the valvular tips always well anterior to the posterior end of the suture (posterior angle, 195–276°). In Trachurus the posterior margin varies from slightly concave to markedly concave (Figs. 23–25) with the valvular tips slightly anterior to well posterior to the end of the suture (posterior angle, 150–210°), and averaging out immediately opposite the end of the suture. In Usacaranx the spores vary from shorter, more stubby forms, to more clongate ones (Figs. 26–27), usually with the posterior margin somewhat concave. Variations in spore breadth result in placing the valvular tips well anterior to the sutural tip or somewhat posterior to it, with the average somewhat in front of the end of the suture (posterior angle, 160–213°). In Helicolenus the range of shapes is much like that seen in Usacaranx, with similar ranges in the posterior angle (168–228°) and almost identical means (Figs. 28, 29).

In the majority of spores the valves are nearly equal in length. In all of the hosts, spores with valves of slightly different shape are not uncommon, one valve usually being more inflated, and the other terminating in a somewhat narrower tip, and often being somewhat more curved. The more slender valve is often evident in capsular view as well as sutural view (Figs. 14, 16). Dissimilarity of valvular shape is especially prevalent in the material from Trachurus. The valves meet in a distinct, but not prominent suture which is slightly elevated. In capsular view the spore is straight, or nearly so, and as the thickness tends to be somewhat less than the height in many spores, may appear somewhat flattened.

The two polar capsules are nearly spherical, and while small, are essentially proportionate to the size of the spore. They are placed near, but not at the anterior margin, and are somewhat rotated when seen in capsular view. They are usually somewhat convergent on the suture. They are opaque, the filament being invisible in fresh spores. Capsulogenous nuclei usually persist as small, pycnotic nucler adhering to the capsular walls.

The sporoplasm fills the spore cavity in fresh spores, or the greater portion of it. When it does not fill the spore cavity, it may be either symmetrical or asymmetrical in position. It is finely granular, transparent, and usually contains a few small, refractive spherules which disappear in permanent preparations. It is binucleate, the nuclei being vesicular and, in most instances, placed rather close together (Figs. 17–19).

Spore Variability. There is a considerable range of variability seen in the spore populations within each host. This variability is not remarkably greater than that seen in other Ceratomyxa (see Tables V and VI), but is unusually extensive if all of these strains belong to the same species. Jameson (1929, p. 63) says of his C. inconstans, obtaind from Scomber japonica, “The front edge is always strongly arched, but the posterior one may be anything from very straight to strongly concave and the ends of the valves vary from very blunt to sharply pointed.

The two valves of a spore may vary in different directions. At first one feels that abnormal spores are being studied, but when different fish on different days are always found to offer the same picture one is forced to believe that we are dealing with a very variable spore.” It should be noted that in none of the hosts was such an extensive series of variations seen as those implied by Jameson, but if all of the hosts are included, then about the same range of shapes have been found in the New Zealand material.

In actuality, the spore populations seen in the four host species appear to fall naturally into three discrete strains, those in Usacaranx and Helicolenus belonging to the same strain. This is shown most clearly if we take the central 60% of the various populations for the various dimensions, particularly the angular ones, as these are independent of fixation, to some extent, and the material from Scomber was fixed prior to its study. The range of the anterior, posterior and tangential angles for the median 60% of the spores from the different hosts are, respectively, Scomber, 112–128°; 202–229°; and all 180°; Trachurus, 90–110°; 175–192°; and 142–175°; Usacaranx, 98–109°; 180–205°; and 146–176°; and Helicolenus 104–120°; 102–207°; and 152–176°. Throughout, the Scomber material tends to be more straight, with little overlap with the other three, while the Trachurus material tends to be more curved, although with more overlap with the intermediate strain from Helicolenus and Usacaranx.

It is not clear whether these may be thought of as host-induced strains or should be thought of as distinctive. Many more hosts must be examined before concluding that the differences seen in the forms the various hosts are stable ones. Neither is it conclusive that the forms seen here are actually identical with the strain seen by Jameson. Since Jameson measured fixed spores, reporting a breadth range of 11.2–13.33μ, it is evident that the material from California has larger spores than that from New Zealand, and the disparity in spore height is even greater. This may be explained on the basis of a certain amount of flattening of some spores, which often occurs in prepared mounts. On the other hand, Jameson speaks of nearly spherical spores, which were not seen in the material from any of the New Zealand hosts. However, immature spores of this, as of other Ceratomyxa, are very broadly oval (Fig. 20), and if Jameson included any immature spores in his measurements, this may account for some of the discrepancy. In view of the kind of variability seen in the various host species allied to the mackerels, and the existence of Jameson's variable species, it seems most probable that they are identical.

The relationship of C. inconstans to C. parva (Thélohan, 1895) is not clear. C. parva is somewhat smaller than C. inconstans, as measured by Jameson, but is much closer to the size recorded in the New Zealand material. C. parva is shown as having a small, arcuate spore, not unlike those seen in Trachurus. There is no information concerning the amount or kind of variability occurring in C. parva, but as it occurs in Scomber scombrus, there can be little doubt of its close kinship with C. inconstans. If it can be shown that the Ceratomyxa of Scomber scombrus are also variable in form, it will be evident that all of these forms can be referred to C. parva.

Ceratomyxa faba n. sp. (Text-fig. 3, Figs. 30–33).

Habitat. This species was found in the gall bladder of a single Caulopsetta scapha (Forster). It occurred as a relatively heavy infection, mixed with C. laxa and C. torquata. The infected fish was taken in August by a trawler working out of Wellington.

TrophiC. Stages. As the trophozoites had largely deteriorated, and there were several species present, no attempt was made to distinguish between the various types.

Spore Dimensions. Breadth, 10.7–14.1μ (12.7μ); height, 5.6–6.7μ (6.2μ); thickness, 6.1 7.0μ (6.4μ); valvular axes, 5.6–8.4μ (6.9μ) and 4.5–7.3μ (5.6μ); capsular diameter,

2. 0–3. 1μ (2.4μ). Anterior angle, 66–129° (99°); posterior angle, 150–239° (200°), tangential angle, 125–180° (162°). Curvature index, 61°, taper index, 38°; valvular index, 101°. Breadth: height ratios of quartiles of breadth range, 1.82, 1.94, 2.15, and 2.16.

Spore Morphology. The small, stubby spores are gently curved toward the posterior margin, and have fairly large polar capsules. The anterior margin is strongly convex in sutural view, and is sometimes slightly indented at the suture. In the majority of spores it is unbroken at the suture, and its curvature grades into the terminal curvature of the valves without any evident inflection. The posterior margin is usually nearly straight, with a very gentle concavity which is sometimes more evident near the suture. In some spores an angle is formed at the suture (Fig. 30). In some spores the posterior margin very nearly parallels the anterior margin, with very little valvular taper, while in others the two are not parallel, and there is a moderate taper (Figs. 32, 33). The valves generally terminate in extremely broad extremities. They meet in a rather indistinct, slightly elevated suture, straight or nearly so. The spore valves may be equal or somewhat unequal in axial length, but are generally rather similar in shape. Despite the concavity of the posterior margin, the valvular tips are usually well anterior to the end of the suture in the majority of spores. In capsular view the valves are broadly rounded, with little taper. The spore is straight or nearly so, and slightly flattened, with the thickness somewhat less than the height.

The relatively large polar capsules lie near the anterior margin. They converge somewhat on the suture, and are nearly spherical to somewhat oval. In capsular view the capsules are opposite, or slightly rotated (Fig. 31). The capsulogenous nuclei are usually persistent, although all other remnants of the capsulogenous cells disappear.

The sporoplasm fills the spore cavity. It is quite transparent, and contains a few refractive spherules, in addition to two small, vesicular nuclei. It usually extends upward slightly between the capsules.

Spore Variability. The spore form shows considerable variability insofar as the range of its angular measurements is concerned. The central tendency in this species is much like that of C. inconstans, which it resembles very closely in the general spore form and angular measurements. The median 60% of the spores lie between 93° and 100° for anterior angle, 190–213° for posterior angle, and 154–174° for the tangential angle. All of these values are very close to those seen in C. inconstans, and quite similar in range.

Discussion. Although many species of Ceratomyxa have been reported from flat-fishes, none are in the general size range of this form. The average spores of this species fall into group I-A-1, with a fairly large number in I-B-1. Despite the stubbiness of the spores, the angular measurements would suggest that it might also be compared with the species in group II-A-1. Of the various species found in these groups, it is evident that it is most similar to C. minuta, C. inconstans, C. gracilis and C. obesa.

It may be distinguished from C. minuta by its larger size and smaller polar capsules. It is more flattened posteriorly than C. gracilis, and the spore form is shorter and stubbier (Jameson, 1929). The spores of C. obesa are not as high in proportion to their breadth, and are somewhat larger, with a breadth of 13.2–14.8μ in fixed state.

There are many similarities between C. faba and C. inconstans. The range and means of the linear and angular measurements are very similar, and the median 60% of the spores exhibit ranges similar to those seen in strains of C. inconstans, and which overlap them to a considerable extent. The difference in any of the linear dimensions between C. faba and C. inconstans is well within the range that may be expected in different host animals of the same species On the other hand, when samples differ to this extent in forms obviously belonging to the same species, they tend to differ proportionately, with the different samples showing a similar breadth: height ratio. C. faba spores have a breadth-height ratio much nearer the border line between the Ceratomyxa and Leptotheca than does C. inconstans, and in view of the marked difference in choice of host, they have been tentatively considered as a distinct species, and designated as C. faba n. sp.

Ceratomyxa castigata n. sp. (Text-fig. 3, Figs. 34–8)

Habitat This species occuried in the gall bladder of two of five Congiopodus leucopaecilis (Richardson). The infected fishes were taken by trawlers working out of Wellington in December and January. In one host the infection was mixed

with C. gibba, and in the other it was mixed with Sphaeromyxa. The bile was thin and yellowish. In neither organ was there any evidence of inflammation.

Trophic Stages. There are many small, rounded to pyriform trophozoites about 5μ in diameter Pyriform trophozoites have a definite posterior process, and a few move sluggishly No clavate small trophozoites were seen. Larger trophozoites, some containing nearly fully developed spores, were also abundant. These were rounded, amoeboid, or clavate, with a few essentially pyriform. Apparently there is a tendency for the trophozoites with developing sporoblasts to forsake the pyriform shape, and assume a clavate or amoeboid form. Larger, rounded trophozoites containing two well-developed spores measure from 18–20μ in diameter Clavate forms may be up to 55μ or 60μ in length. While the majority of trophozoites are disporous, a few monosporous ones are found (Fig 34)

The trophozoites are rather transparent, with homogenous to very finely granular ground plasm. There are very few inclusions, these taking the form of small, irregular granules, about 0.25μ in diameter, or larger, refractive bodies, about 1.0–1.5μ in diameter. The latter give an oily appearance, but are not selectively stained by either Janus green or neutral red. There is little evidence of ectoplasmic differentiation in the tiniest trophozoites. In some of the larger trophozoites the ectoplasmic layer is distinct, forming a continuous zone around the body In others it can be seen only in pseudopodia.

Spore Dimensions. Based on measurements from two hosts. Breadth, 9.2–15.3μ (13.1μ), height, 5.1–6.9μ (5.9μ), valvular axes, 6.1–8.0μ (7.3μ) and 5.4–7.7μ (6.2μ); capsules, 1.6–3 3μ (2.2μ) by 1.6–2.5μ (2.0μ), and 1.6–2.5μ (2.1μ) by 1.5–2.2μ (1.7μ) Anterior angle, 100–129° (113°); posterior angle, 181–223° (206°); tangential angle, 155–180° (172°) Curvature index, 41°, taper index, 34°, valvular index, 93°. Breadth: height ratios for quartiles of breadth range, 1.93, 2.06, 2.15 and 2.41.

Spore Morphology. The small, flattened to slightly curved spores have slightly unequal valves, and often have slightly unequal capsules. In sutural view the anterior margin is convex, with some tendency for the margin of the longer valve to be flattened or slightly concave (Fig. 38). The posterior margin varies from convex to concave (Figs. 35, 38), but in the majority of spores is flattened or slightly concave. One valve is often somewhat more curved than the other. The contour of both anterior and posterior margins is unbroken at the suture. There is at the most a very moderate valvular taper, and the valves terminate in very broadly rounded tips. The spores are not flattened in capsular view, the cross section being approximately circular. The suture is often slightly curved, or oblique, and is narrow.

The polpar capsules are equal or slightly unequal. The disparity in size is never strongly marked, but the smaller capsule is often noticeably more slender. They are broadly oval, and opaque, and narrow sharply at the neck. They are slightly rotated when seen in capsular view, and converge slightly on the suture. The filament cannot be seen in living spores. It measures up to 30μ when extruded Capsulogenous nuclei are persistent. In many spores there are somewhat basophilic remnants of the capsulogenous cells. forming a small mass of material near the capsular foramina.

The sporoplasm is large, completely filling the posterior part of the spore cavity in fresh spores. It is transparent, finely granular, and contains two vesicular nuclei with no definite locus. There are several small refractive spherules in the majority of the spores. These are sometimes persistent in Giemsa preparations (Fig. 36).

Spore Variability. As with other small-spored Ceratomyxa there is a moderate range of spore shapes, associated with differences in the contour of the posterior margin of the spore. Capsules are equal or somewhat unequal, and there are small differences in the contour of the shell valves. The median 60% of the spores have angular measurements of 101–126°, 200–216° and 170–180° for anterior, posterior and tangential angles, respectively.

The population samples from the two hosts were very nearly perfect matches. The differences between the two means for the linear dimensions were breadth, 0.2μ; height, 0.0μ: valvular axes, 0.4 and 0.1μ, and capsular diameter, 0.2μ. The differences in the means of the angular measurements were: anterior angle, 2°; posterior angle, 1°; and tangential angle, 4°. It is evident that insofar as the samples measured reflect the populations in the two hosts, they were extremely similar. It is interesting to note that one host was quite small, while the other was unusually large. Apparently the size of the host is not an important factor in spore morphology in this species.

Discussion. No Ceratomyxa have been described previously from hosts belonging to the Congiopodidae, although the same host is also infected by C. gibba in New Zealand. The larger size and greater curvature of the spores of C. gibba make it easy to distinguish between them.

The typical spores of this species fall into group I-A-1, with some showing sufficient valvular taper to approach group I-B-1. Of the species other than.

C. castigatoides, to which this species will be compared later, it is most like the small-spored species found in mackerels and their allies, C. minuta and C. inconstans, and like C. faba and C. gracilis. It is larger than C. minuta, with relatively smaller polar capsules. The size difference is not sufficient to guarantee that the two are different, however, for samples of spores from the same hosts belonging to the same species of Ceratomyxa occasionally differ as much as these two. Except for capsular size, the spores have much the same proportion in sutural view, but the spores of C. minuta are more flattened in capsular view, and do not commonly show curvatures or obliqueness of the suture. Moreover, the trophozoites of C. minuta contain a number of persistent, refractive inclusions which are not found in C. castigata. There are significant differences in the angular measurements and indices of C. castigata and the strain of C. inconstans seen in Scomber, in which the spores are more curved and have more taper. It is most like the forms seen in Usacaranx and Helicolenus. The differece in linear dimensions is not sufficient to ensure that the two forms are different, and there is considerable overlap in the general contour of the spores and the correlated angular measurements, although differences appear, particularly in the tangential angles of the median 60% of the population samples of the three strains. Despite the similarity, however, the tendency toward a curvature of the suture, and the larger polar capsules, often of slightly different size, in C. castigata makes it improbable that they are actually identical.

The spores of C. faba are stubbier than those of C. castigata, with a lower breadth: height ratio. According to Jameson (1929), the spores of C. gracilis, although having a breadth similar to that of C. castigata, are considerably more slender, with a height range of 4–5.6μ. (Mean height, 5.9μ in C. castigata.) The spores of C. gracilis are also oval, without the flattened or slightly concave margin seen in C. castigata. As it does not appear to be identical to any of the previously described species, it has been designated as C. castigata n. sp.

Ceratomyxa castigatoides n. sp. (Text-figs. 3–4; Figs. 39–44).

Habitat. This species occurs in the gall bladder of Pseudolabrus coccineus (Bloch and Schn). Only a single specimen of this species was examined. It was taken by a trawler working out of Wellington in August. In addition to this species, a light infection with a larger, unidentified species of Ceratomyxa was also present. There was no evidence of irritation of the host organ.

Trophic Stages. The trophozoites were not studied exhaustively in life, and as a second infection was not located, there is but little information concerning them. There were many small trophozoites of about 5μ or somewhat less, and fewer large ones. No distinction between ectoplasm and endoplasm was observed in the trophozoites. There were no refractive inclusions, and the protoplasm was very clear and transparent. Most of the larger trophozoites were disporous, at least, although a few isolated spores were seen with small amounts of protoplasm about them. As most of the protoplasm appears to be exhausted during spore formation. It was thought possible that these might be spores arising from monosporous trophozoites. In fixed material it was noticed that there were many spores attached together at right angles, without any constancy in the surfaces which were in contact. Occasionally small groups of three to six spores were found attached together. It is not known whether this indicates that some trophozoites are polysporous, or that they sometimes tend to aggregate. In view of the small size of the trophozoites seen, the latter seems to be the more probable Disporous trophozoites measured about 20μ in diameter.

Spore Dimensions. Based on measurements taken of spores fixed in sublimate-acetic, stored in alcohol, and studied in water suspension. Breadth, 9.8–17.8μ (14.7μ); height, 5.1–7.3μ (5.9μ): thickness, 5.8–7.3μ (6.3μ); valvular axes 5.1–9.8μ (6.8μ) and 5.1–8.7μ (6.0μ); capsular diameter, 1.8–2.6μ (2.0μ). Anterior angle, 9–124 (108°); posterior angle, 190–248 (209°); tangential angle, 161–180° (168°). Curvature index, 73°; taper index, 41°; valvular index, 101°. Breadth: height ratios for quartiles of breadth range, 1.64, 2.07, 2.10 and 2.20.

Spore Morphology. In general shape and appearance, the spores are rather simiiar to those of C. castigata, but are somewhat larger and have equal polar capsules. In sutural

view the anterior margin is convex, curving over the sutural region without interruption. One valve is not uncommonly less inflated than the other (Fig. 40). In such spores the lateral half of the more slender valve is flattened or slightly concave. In a few spores the posterior margin is flattened (Fig. 44), but in most spores it is gently to moderately concave. The range of spore shapes is essentially that between Figs. 44 and 42. The valvular taper is quite moderate, and the valves terminate in very broadly rounded tips. They are equal to slightly unequal in length, and meet in a straight suture, slightly elevated, and varying somewhat in prominence. In fresh spores it was noted that the suture often sat in a very shallow depression running about the spore, but this could not be seen in fixed spores. In some spores stained with haematoxylin, the suture stained as a double line (Fig. 42). In capsular view most of the spores are straight. In a few there is a slight tendency toward curvature, which is never marked. The disparity in valvular diameter often gives the spores a slightly boatshaped outline.

The two equal polar capsules are nearly spherical in fresh and fixed material studied in water suspension, and broadly pyriform in permanent slides, with very narrow necks. They are set some distance from the anterior margin, and are not opposite when seen in capsular view. It appears, however, that they tend to converge on the suture, and to be convergent rather than divergent, slanting toward the main axis of the spore In fixed spores the filament cannot be seen In fresh spores it can be seen, but indistinctly, and the number of coils has not been determined. The capsulogenous nuclei are sometimes persistent, but are very small in mature spores. There are no other remnants of the capsulogenous cells.

The sporoplasm fills the fresh spore. It is highly transparent, but contains a few small, refractive bodies which disappear in fixed spores, even prior to dehydration. The two vesicular nuclei usually lie close together.

Spore Variability. Although the spore varies markedly in size, the largest spores being nearly twice as broad as the smallest spores, the general contour is relatively stable. Spores are never really convex posteriorly, and are never sharply curved. Sixty per cent. of the sample measured between 10.9μ and 14.1μ had anterior angles between 96° and 117°, posterior angles between 190° and 215°, and tangential angles between 157° and 180°.

Discussion. The wrasses are often hosts to the Ceratomyxidae C. linospora, C. inaequalis, and C. arcuata have been reported from various members of the Labridae (see Kudo, 1920), while C. coris and Leptotheca fischeri have been found in members of the Coridae (Kudo, 1920; Jameson, 1931). This species has much smaller spores than those of C. inaequalis (31μ, according to Doflein, 1898); much straighter spores than C. arcuata, and lacks the appendages of C. linospora (Doflein, 1898) Ceratomyxa coris is something of a mystery as Georgévitch (1916) neglected to mention the dimension of its spores, and has drawn a spore which appears to be immature (see Kudo, 1920, Fig. 48). It is not clear whether the spores all retain this juvenile character, and as the drawn spore has the breadth: height ratio of a Leptotheca, its taxonomic position is questionable. In general appearance it is not unlike young spores of C. castigatoides, but until it has been described more fully it will not be possible to reach a final conclusion.

Spore shape places this species in group I-B-I, or, when most curved, into II-B-I. Of the species in these groups, it is most similar to C. castigata. Since the spores measured had been fixed and were somewhat shrunken, the spores of C. castigatoides are somewhat larger than those of C. castigata Spore breadth is similar enough to prevent its use for separation of the two species, as are the other dimensions, taken alone. The breadth: height ratio is consistently lower in C. castigatoides, however, and the spores have a greater valvular index. The lack of curved sutures, the equality of the polar capsules, and the tendency of the spores to adhere in pairs, as well as the smaller quantity of residual protoplasm after spore formation in C. castigoides, all seem to indicate that despite the similarity in spore dimensions, these are not identical.

C. castigatoides differs from the smaller C. inconstans in size, probably to a significant extent, at least for identification purposes. The capsules are larger, and the spores have a lower breadth height ratio. They are more curved than the spores of C. obovalis (Fantham, 1930), and somewhat less Leptotheca- like.

Of the species in group II-B-I, C. castigatoides differs from C. declivis in being less curved, and in having a more slender shape, as well as in the reaction of the spores to Giemsa Since the form cannot be equated with any of the previously described species, it has been designated C. castigatoides n. sp.

Ceratomyxa declivis n. sp. (Plate III, Figs. 45–49)

Habitat. This species occurs in the gall bladder of Cyttus novae-zelandiae (Arthur), and probably in the gall bladder of Cyttus australis Richardson as well. Two infected fishes of the former species were seen, both taken by trawlers working out of Wellington, in July and August. In August one very lightly infected Cyttus australis was also taken, apparently with the same species In none of the hosts was the gall bladder or bile duct inflamed.

Trophic Stages. The trophozoites, immobile and rounded when examined, are transparent, apparently without the spherical inclusion often seen in Ceratomyxa. Only lobopodia were seen, but as the material was not fresh little can be sad of the range of trophozoite shapes or pseudopodia. The smallest trophozoites measure about 8μ in diameter, and are multinucleate Large trophozoites reach 25μ in diameter. Most of the trophozoites are disporous, although some unisporous ones occur. The small trophozoites are apparently formed as the result of gemmule formation (Fig. 49). A few trophozoites with dividing nuclei were seen. These have four chromosomes (Fig. 45).

Spore Dimensions Based on spores from one Cyttus novae-zelandiae Breadth, 13.5–15.2μ (14.4μ); height, 5.1–6.8μ (5.9μ); thickness, 5.1–6.2μ, (5.6μ); valvular axes, 7.2–9.0μ (8.4μ) and 6.8–7.9μ (7.3μ); capsules, 1.7–2.8μ (2.4μ) by 1.7–2.2μ (2.0μ). Anterior angle, 87–105° (97°); posterior angle, 163–186° (175°); tangential angle, 132–155° (145°). Curvature index, 88°; taper index, 30°; valvular index, 78°. Breadth: height ratios for quartiles of breadth range, 2.65, 2.27, 2.51 and 2.57.

Spore Morphology. The small spores are plump crescents, with rounded, almost truncated tips. In sutural view the anterior margin is convex, curving smoothly over the suture. The posterior margin of each valve is nearly straight, but meet at an angle at the suture in fresh spores. In permanent slides, however, the posterior margin tends to appear as a concave, curving margin (Figs. 46, 47). The two valves tend to be equal or slightly unequal, the differences between them never becoming prominent. In some spores one of the valves is slightly more slender than the other, and curves more sharply. In capsular view the spores are straight (Fig. 48). The straight suture is slightly elevated, and not very prominent. The spore membrane is very delicate, and rather easily deformed.

The two polar capsules are broadly oval to spherical. They lie near the anterior margin. While they appear to be opposite when seen in capsular view, they are slightly divergent, the foramina being more lateral than the body of the capsule. The filament is but indistinctly visible in the fresh spores. It appears to form four or five coils. The capsulogenous nuclei are usually persistent.

The sporoplasm very nearly fills the fresh spore, but is greatly shrunk by fixation. In fixed and stained spores its position is variable, but it tends to adhere along the posterior margin of the spore membrane. It is rather granular in fresh spores. A number of small, refractive spherules are seen in fresh spores. These are rarely more than 0.5μ in diameter, and usually a good deal smaller. These bodies disappear in fixed and stained spores. The two vesicular nuclei are small, and variable in position.

A prominent feature of the spore is the presence of a number of bodies, oval to somewhat irregular in shape, which adhere to the spore membrane and stain intensely with the eosin colour of Giemsa's stain. These are apparently not identical with the small inclusions seen in the fresh spores, and cannot be seen in haematoxylin preparations In many spores they occur in such numbers that the sporoplasm, and even the capsules, are obscured. They occur in both immature and mature spores. It is interesting to note that similar granules occur in two other species of Ceratomyxa with curved spores, C. arcuata and C. flexa.

Spore Variability. The spore varies somewhat in curvature and in the amount of valvular taper. All spores are at least gently curved, however, and the range of variability is less than that seen in many Ceratomyxa For anterior, posterior and tangential angles, respectively, 60% of the sample were in the ranges between 93–102°, 166–183° and 134–150°.

Unfortunately, the infection was so light in the Cyttus australis that it was not possible to undertake a careful analysis of any differences between the spores in the two host species. The few spores that were measured fell into the same size range, and exhibited the same general properties. There can be little doubt that the two samples belong to the same species.

Discussion. The only previously recorded ceratomyxid parasite from members of the Zeidae is Leptotheca vikrami, described by Tripathi (1948) from Zeus faber.

There are few similarities between L. vikrami and the present form. The spore shape places this species in group II-B-1. Of the species in this group, C. inconstans is significantly smaller, and more variable, and except for the strain from Trachurus, less curved. Some of the spores of C. castigatoides are as bent as this species, but only those near the end of the range of variability. The curvature index, 43° in C. castigatoides, is 88° in C. declivis. The unusual staining reaction in Giemsa also serves to distinguish C. declivis from all of the smaller curved species seen in New Zealand material.

It would appear that C. declivis is probably more closely allied to C. flexa and C. arcuata than to any of the other species found in New Zealand material. Both of these species have spores which are significantly larger than those of C. declivis, and are more sharply arcuate, but both also have the prominent eosinophilic granules in Giemsa-stained material. As this form appears to be distinct from all previously described species, the name C. declivis n. sp. is proposed for it.

Ceratomyxa intexua n. sp. (Text-figs. 4–5; Figs. 50–57).

Habitat. This species occurs in the gall bladder of Jordanidia solandri (Cuv. and Val.). Two of five fishes were infected. They were taken by a trawler working out of Wellington in August. A third hake, taken in July, may also have been infected. In addition to having a few spores of Leptotheca annulata in its bile, there were several spores which closely resemble C. intexua. It may also occur in Plagiogenion rubiginosus (Hutton). In a specimen containing a heavy infection of C. flexa, a few spores were found which appeared to belong to C. intexua. There were not enough to make a positive identification possible, however. The two hake which were heavily infected with C. intexua had gall bladders which were red and inflamed, especially near the junction of the gall bladder and bile duct.

Trophic Stages. The smallest trophozoites are very tiny, measuring about 1.5μ in permanent preparations. They tend to be rounded, and have clear, transparent, inclusionfree protoplasm. As the trophozoites increase in size they are less often rounded, becoming irregular, with lobopodia, or extremely irregular, with long, slender, often branching pseudopodia. Like the younger forms, the older trophozoites are quite transparent. It is not until they approach full size that a few granular inclusions, and an occasional spherical inclusion of an inconspicuous type, appear. Although the nuclei cannot be seen in the living organisms, the sporoblasts are visible early in development.

Isolated trophozoites carrying two spores are not uncommon. Small clusters of trophozoites, containing spores in multiples of two are also seen. The smallest trophozoites show no tendency to aggregate, but as the sporoblasts appear the great majority of the trophozoites appear to aggregate in smaller or larger groups. Sometimes several hundred individuals are combined in a very large mass. Each unit of the aggregation is joined to the others by the intimate union of slender, intertwined pseudopodia. The limits of the individual organism are apparently lost in these aggregations, for no plasmalemma can be seen crossing the pseudopodial connections between them. As the spores mature the material of the trophozoites becomes more tenuous, and eventually masses of spores, held together temporarily by a delicate reticulum appear. Delicate remnants of the empty reticulum are also found. It is not uncommon for Ceratomyxa trophozoites to aggregate, but the intimacy and permanence of the union in this species is certainly unusual.

Spore Dimensions Breadth, 9.3–20.1μ (15.4μ); height, 3.4–5.4μ (4.4μ); thickness, 3.5–4.3μ (3.9μ); valvular axes, 5.0–10.8μ (8.6μ) and 4.5–9.8μ (7.4μ); capsules, 1.2–2.2μ (1.8μ). Anterior angle, 93–135° (120°); posterior angle, 150–205° (180°); tangential angle, 130–180° (167°). Curvature index, 60°; taper index, 13°; valvular index, 60°. Breadth height ratios for quartiles of breadth range, 2.62, 3.03, 3.37 and 3.92.

Spore Morphology. The elongated, slightly curved spores terminate in moderately narrow, rounded tips. In sutural view the anterior margin is convex, unbroken at the suture or slightly indented In some spores the lateral two-thirds of one valve is somewhat flattened, with a corresponding inflection of the anterior margin (Fig. 51). The posterior margin varies from flat to somewhat concave. It is usually smoothly curved over the suture, but in some spores it is slightly angled at the suture. The suture is inconspicuous, narrow, and only slightly elevated. In some spores it sits in a slight depression at the anterior face of the spore. The two valves are sometimes equal, and occasionally quite unequal (Fig. 53). In capsular view the spore is straight or slightly bent (Figs. 52–3). The spore is very slightly flattened in profile, but it is not a conspicuous feature.

The small polar capsules are nearly spherical. They lie near the anterior margin, through which they open, and are opposite, or nearly so, in capsular view. The filament cannot be seen in living spores. Capsulogenous nuclei are persistent, and in some spores remnants of the capsulogenous cells can alse be seen (Fig. 54).

The rather small sporoplasm is transparent, and without conspicuous inclusions. It contains two vesicular nuclei. It is variable in position. A few small refractive spherules are found in most fresh spores, but these are missing in fixed and stained spores.

In this species spore development is completed after the trophozoites have been placed on the microscope slide, hundreds appearing in depressions. The impression was gained that more spores were formed than the number of trophozoites present in the depressions initially would have formed Davis (1917) reports a similar experience with C. lunata. He states (p. 226–7), “The great variability in the spores was probably due to the fact that they were, for the most part, fomed under abnormal conditions after the trophozoites had been placed on a slide and covered with a cover glass sealed with parafin Spores formed under such conditions are often smaller than those produced under more favourable conditions.” As it happens, a sample of spores had been measured immediately after a depression slide was prepared, on a Friday afternoon. On the following Monday the slide was re-examined, and it was evident that a very large number of new spores had been produced. A second spore sample was measured and compared with the first. The second sample was somewhat more variable, and had a somewhat greater incidence of abnormal spores. The mean dimensions of the two samples were essentially the same. It may be that this species is more stable than C. lunata, less sensitive to the environment in depression slides, or that many of the spores in the original sample had been formed after the death of the host, and were already abnormal. The laboratory temperatures at Wellington are considerably cooler than those at Beaufort during the summer, which may also have been a factor In view of the very marked variability in size of C. intexua, it seems scarcely likely that it is a highly stable species, and it is more probable that the original population of spores were somewhat abnormal, or that the conditions favoured a more normal development.

A small number of spores were found in a Plagiogenion rubiginosus which were very like the spores of C. intexua. The host was heavily infected with C. flexa, a species with strongly curved spores having relatively slender valves, and it is not certain whether they were unusually straight spores of C. flexa, or actually belonged to another species Spores like them did not occur in other Plagiogenion infected with C. flexa, however. Although the length of the valvular axis is about the same in C. flexa and C. intexua, the sutural diameter is greater in C. flexa, and the polar capsules are somewhat larger. The few spores which were relatively straight had smaller polar capsules, and a somewhat smaller sutural diameter (Figs. 56, 57). A positive identification, however, could not be effected with so little material.

Spore Variability. There is a considerable variation in the size of the spores from a single host, and some spores have more tapered valves than others. There is a considerable difference in the relative equality of the valves in different spores. The most prominent variation, however, is in spore breadth In this species the spores are quite transparent, and the capsulogenous cells are very difficult to see in fresh spores. As the valvular nuclei disappear early, it is not impossible that some of the variability has resulted from including immature spores in the samples. The wide range of spore breadths is indicated by the fact that the median 60% of the spores vary in breadth between 13.2μ and 18.1μ.

Sixty per cent of the spore population have anterior, posterior, and tangential angles of 116–128°, 173–194°, and 160–177°, respectively. It is evident that despite the variation in spore breadth, he spore shape is not unusually variable. The spread covered by the median 60% is essentially comparable to that seen in other Ceratamyxa species Spore height and thickness are not as variable as spore breadth. The breadth height ratios of the various quartiles of the breadth range reveal a rapid increase in breadth, proportionate to height. It seems possible that this may be one of the factors which tends to favour an unusually variable spore breadth However, in some of the larger, slender species of Ceratomyxa in which there is also a great difference in the breadth, height ratios of the various quartiles, no such marked variability in breadth was seen.

Discussion. No Ceratomyxa have been reported previously from the Gempyllidae. In the New Zealand material, C. minuta has been seen in Jordanidia as well as Thyrsites atun The small size and conspicuous inclusions of the trophic stages of C. minuta make recognition of the two species easy.

C. intexua falls into group II-A-1 or II-B-1, depending on the amount of valvular taper. Of the species in these groups, none are very similar to C. intexua The aggregative activities of the trophozoites are not reported for any of the similar species. The spores can be distinguished from those of C. inconstans by their greater

breadth and more slender shape. The same criteria distinguish them from C. faba, and while the spores of C. obesa are more similar in breadth, they are also much less slender (Jameson, 1929). While there is a considerable range of dimensions and shapes recorded for C. obovalis (Fantham, 1930), none of these have a breadth: height ratio comparable to that seen in C. intexua. Since the species cannot be equated with any of the previously described species, it has been designated C. intexua n. sp.

Ceratomyxa recta n. sp. (Text-fig. 5, Figs. 58–62).

Habitat. This species occurs in the urinary bladder of Genypterus blacodes (Bloch and Schn.). It is not a common form, as it was seen in but a single ling, taken in the Wellington area in September.

Trophic Stages. The rounded, amoeboid, or clavate trophosoites reach a maximum size of about 35μ. Only lobopodia have been seen. No moving trophozoites have been observed, but the pseudopodia are apparently used, in part, at least, for attachment to the host organ.

The protoplasm is dark, and rather coarsely granular. No spherical or other prominent inclusions are present. Despite the darkness of the protoplasm, no definite ectoplasmic layer can be seen, even in pseudopodia. The trophozoites are unisporous. A considerable quantity of protoplasm remains at the end of spore formation. There appears to be a single residual nucleus (Fig. 58).

Spore Dimensions. Breadth, 14.7–16.7μ (15.6μ); height, 6.8–8.8μ (7.8μ); thickness, 6.8–8.3μ (7.8μ); valvular axes, 7.3–8.8μ (8.1μ) and 7.1–8.3μ (7.6μ); capsular diameter, 2.0–3.4μ (2.6μ). Anterior angle, 120–134° (120°); posterior angle, 219–240° (230°); tangential angle, 180°. Curvature index, 10°; taper index, 50°; valvular index, 90°. Breadth: height ratios for quartiles of breadth range, 2.07, 2.04, 2.05, 1.90.

Spore Morphology. The spores have an elongated oval shape, with somewhat flattened anterior and posterior margins. In sutural view the valves are equal, and have similar shapes. They meet in a low, rather conspicuous, straight suture. Except for the position of the capsules and sporoplasm, the spores are similar in capsular and sutural views. In some spores the suture sits in a very shallow depression.

The two nearly spherical capsules are placed a short distance from the anterior margin. They are slightly rotated, although they are opposite when seen in sutural view. The filament is visible indistinctly, apparently in the form of four or five coils. Capsulogenous cells persist in spores free from the trophozoites (Fig. 60, 61). At first they are rather dense, but as they age they become vacuolated, and eventually form a delicate membrane, in which the remnants of the capsulogenous nucleus lie, similar to the spores of Leptotheca pinguis. In this species, however, the spore eventually loses the membranes around the capsules.

The sporoplasm is large, nearly filling the spore cavity. It is rather granular and opaque in fresh spores. A few refractive spherules sometimes occur in or near the sporoplasm. The two vesicular nucle are usually placed close together, and have rather conspicious peripheral chromatin.

Immature spores have very conspicuous valvular nuclei, located at the tips of the valves, and embedded in the thickened substance of the membrane (Fig. 61). These nuclei persist, and may be seen in fresh spores, as well as in stained ones, giving the spore a permanently juvenile appearance.

Spore Variability. The spore is remarkably constant in shape Lacking any tendency toward curvature, and with no valvular taper, it appears to be devoid of the traits which are most often variable in other species. The range of variation is about that seen in Figs. 59 and 62.

Discussion. The only Ceratomyxa previously reported from a member of the Ophidiidae is C. arcuata, which occurs in the gall bladder of Ophidium vasalli (Kudo, 1920). It bears very little resemblance to this species. C. hokarari and C. inversa have also been found in Genypterus in the Wellington area. Both occur in the gall bladder, and one is strongly curved, while the other is very slender.

The species belongs in group I-A-1. The only species in its general size range occurring in that group is C. dubia (Dunkerly, 1921), a biliary parasite of Cottus bubalis. The greater breadth: height ratio of C. dubia, as well as its choice of host organ, make it extremely unlikely that the two forms are identical.

Immature spores bear a strong resemblance to the figures of Georgévitch depicting C. coris (see Kudo, 1920, Fig. 48), and to a lesser extent, C. herouardi

(Kudo, 1920, Fig. 49). Georgévitch may have been dealing with species which, like this one, retains a more or less permanent juvenile appearance. Although no dimensions are given for these species, it is highly improbable that either are identical with C. recta, as both are biliary parasites.

This species lies at the border line between the Leptotheca and the Ceratomyxa. It has been placed in the Ceratomyxa as a result of a statistical accident, as it were, the mean breadth being just over twice the mean height. It is interesting that in this species there was no evidence of an increasing breadth: height ratio in the various quartiles of the breadth range. The thickness of the valvular tips, containing the remnants of the valvular nuclei, may tend to prevent the lateral expansion of the spore valves during the later part of spore formation. For whatever reason, the relationship of height to breadth is somewhat different in this species than in most members of the group. Its similarity to the Leptotheca calls for examination of that genus for possible identification. Of the members of that genus, it is perhaps closest to L. pinguis, from which it differs in being considerably broader in comparison to its height, and L. lobosa (Davis, 1917) It differs from L. lobosa in having a straight suture, and anterior and posterior margins which are alike As this form is evidently undescribed, it has been given the name C. recta n sp.

Ceratomyxa flexa n.sp. (Text-fig. 5, Figs. 63–7)

Habitat. This species occurs in the gall bladder of Plagiogenion rubiginosus (Hutton). All three examples of this fish were infected; one possibly contained C. intexua as well. All of the infected fishes were taken by a trawler working out of Wellington in July. There was no evidence of irritation of the infected organs.

Trophic Stages. The trophozoites, immobile when studied, are rounded to amoeboid, and measure up to about 25μ in diameter. Small granules, less than 0.5μ in diameter, and larger refactive spherules occur in the protoplasm. The latter do not persist in permanent preparations. Ectoplasm is never distinct In permanent preparations a number of tiny basophilic bodies, which appear to be more abundant than the granules seen in living organisms, can be seen (Fig 63).

All of the sporulating trophozoites appear to be disporous. The two spores are variously oriented in the trophozoite, but not uncommonly are arranged with their posterior faces in contact, and the lateral portions of the valves curved around each other. In some young; spores just released from the trophozoites, there appears to be a membranous remnant of the sporoblast investing the spore. In young spores the valvular nuclei deteriorate before the capsulogenous cells have disappeared.

Spore Dimensions. Based on spores fixed in sublimate-acetic, stored in alcohol, and measured in water suspension Breadth, 13.6–16.9μ (15.9μ); height, 5.6–7.9μ (5.6μ); valvular axes, 8.2–11.9μ (10.1μ) and 6.5–11.3μ (8.6μ); capsules, 2.3–3.4μ (2.6μ) Anterior angle, 5.3–1.13° (82°); posterior angle, 95–192° (147°); tangential angle, 95–170° (129°). Curvature index, 131°; taper index, 18°; valvular index, 65°. Breadth: height ratio for quartiles of breadth range, 2.17, 2.49, 2.76 and 3.24.

Spore Morphology. The arcuate spores usually have unequal valves, with moderately narrow tips. In sutural view the anterior margin is strongly convex, the curvature passing smoothly over the suture. Occasionally a spore is seen with the lateral third of one valve somewhat flattened anteriorly. The posterior margin is moderately to strongly concave, usually curving smoothly along its whole course, but occasionally slightly flattened in the central region (Fig. 65). The suture is rather inconspicuous in most spores. It is scarcely elevated, and in the majority of spores takes a straight course over the spore surface In a few spores, however, it passes obliquely over the anterior face of the spore, and is slightly curved in sutural view.

The polar capsules are equal, and lie at the anterior margin. They are broadly oval to spherical, with short, slender necks. The capsules sometimes converge a little on the suture, but this is never a conspicuous feature of the spore. In capsular view the sutures are usually opposite, opening at the midline. In spores with an oblique suture, however, the capsules are somewhat rotated in position, with the foramina located about half-way between the spore axis and the lateral margins. The filament is only imperfectly visible in fresh spores. It appears to coil four or five times. The longest filament to be extruded measured 25μ. Although the capsulogenous nuclei are persistent in mature spores, they become very small and inconspicuous (Fig. 64. 66).

The large sporoplasm does not fill the spore cavity. It is rather granular in fresh spores. From one to about six refractive spherules are present in spores. These are often outside of the sporoplasm, which is slightly withdrawn from them (Fig. 64). They are not persistent in stained preparations. The two sporoplasmic nuclei are small, with a small endosome. They usually lie close together.

The spores of C. flexa, like those of C. declivis, contain many bodies of irregular shape which stain deeply in Giemsa preparations and cannot be seen in haematoxylin preparations (Fig. 66). In C. flexa they tend to be less numerous than in C. declivis, to cluster together and from larger masses more often, and to be less exclusively associated with the spore membrane, occurring in the sporoplasm as well. They are not seen in very young spores, just taking form, and are somewhat less abundant in the mature spores.

Spore Variability. The spores vary primarily in culvature, the range being essentially that between Figs. 67 and 65. The valves vary somewhat in taper, but otherwise, except for curvature, their shape is relatively constant. The suture is somewhat variable, and the capsular position is also somewhat variable.

Although occasional spores with much more curved or much straighter shapes are seen, the majority of the spores fall in a fairly narrow range. Sixty per cent. of the spores have anterior, posterior and tangential angles of 74–92°, 131–167°, and 116–142°, respectively, a range somewhat larger than most Ceratomyxa species, but not outstandingly so.

Discussion. No Ceratomyxa have previously been reported from the Theraponidae. Perhaps the closest record is the occurrence of C. arcuata in Pagellus centrodontus, one of the Sparidae (see Kudo, 1920). C. arcuata is larger than C. flexa, with considerably longer valvular axes, although in other respects the two are rather similar.

The configuration of the average spore fits group II-C-1. It is significantly larger than C. parva, and smaller than C. lunata, the only previously described species adjacent to it in this group. Of the species found in New Zealand material, the closest in size is C. gibba, which differs from it in the breadth height ratio, the inequality of the valves, as well as in lacking the eosinophilic material in the spores stained with Giemsa. In many ways it is more similar to C. declivis, from which it differs in its more slender valvular contour, and greater breadth height ratio, as well as in being more curved. As this form is not identical with other previously described species, it has been termed C. flexa n. sp.

Ceratomyxa insolita n. sp. (Text-figs. 5–6, Figs. 68–9)

Habitat. This species occurs in the gall bladder of Dactylopagrus macropterus (Bloch and Schn). It is not common, having been found in but a single host. The infected fish was taken by a trawler working out of Wellington in August.

Trophic Stages. A few trophozoites were seen, rounded and immobile when examined, and probably dead. They are large, oval organisms, reaching up to 300μ in greatest diameter, and had no pseudopodia when examined. They are covered by a rather tough outer covering, apparently ectoplasmic, which in some individuals had become loosened and wrinkled. The endoplasm is very dark, and finely granular, with a tendency toward a fibrillar structure near the extremities. There are many small, granular inclusions and larger, refractive bodies. The latter are not conspicuous. Many spores can be seen within the trophozoites. Although they are numerous, details of structure cannot be seen in whole trophozoites because of the opaquepess of the cytoplasm. It was estimated that some of the trophozoites had as many as 50 spores.

Spore Dimensions. Breadth across widest part of spore, 13.0–20.0μ (16.2μ), height, 10.0–13-μ (11.5μ). valvular axes, 19.0–26.0μ (23.8μ). and 17.0–23.0μ (21.5μ), capsules 10.0–13.0μ (11.5μ) by 3.0–4.0μ (3.2μ), and 7.0–9.0μ (8.5μ) by 2.5–4.0μ (3.4μ) Anterior angle, 16–41° (28°), posterior angle, 22–55° (41°, tangential angle, 13–48° (32°) Curvature index, 291°, taper index, 9°, valvular index, 13° It is evident that breadth height ratios are meaningless in a spore so strongly furcate.

Spore Morphology. The unusual spore is furcate, with large, elongated, unequal polar capsules and asymmetrically placed foramina. The shape of the spore results in all assuming the same orientation in slides, with the sutural view presented. The anterior margin is sharply angled, with a large prominence extending upward at the foramen for the larger capsule, and a smaller one at the foramen for the smaller capsule. The anterior margin of the valves are somewhat convex lateral to the capsular foramina, the convexity extending to the valvular tips in some spores. or being interrupted at a level approximately opposite the posterior end

of the suture in others. The posterior margin tends to be nearly parallel to the more lateral part of the anterior margin, but there is some valvular taper in the most lateral parts of the spore. The valves are sometimes slightly constricted at a point just beyond the posterior end of the suture, where the sporoplasm terminates, but no septum is present. The two valves are always somewhat unequal, due to the differences in the capsular foramina, and usually differ by one or two microns in axial length. Otherwise they are quite similar. They meet in a heavy, prominent suture, which is straight.

The polar capsules are unlike those seen in most Ceratomyxa, being much larger, more elongatedly pyriform, and having the filament loosely coiled, and more or less longitudinally arranged in the smaller capsule. In the larger capsule the filament is tightly coiled, up to 12 coils being present. A central, longitudinally arranged portion of the filament passes from the foramen to the lowermost coil, at least in many spores. It cannot be seen in some. The foramina are very prominent, and project unequally from the anterior margin, the larger capsule always projecting further forward. In some spores the capsules may project beyond the foramina a short distance. In most spores some remnants of the capsulogenous cells can be seen, surrounding the capsules and containing a capsulogenous nucleus. They are rather dark and granular in fresh spores (Fig. 68).

The sporoplasm is large, extending about halfway toward the valvular extremities. It is rather finely granular in fresh spores. It is more or less symmetrical in position, and contains two rather small, vesicular nuclei.

Spore Variability. The spore variability is not unusually great, tending to exhibit some of the tendencies seen in elongated species with empty valvular prolongations. The empty portions of the valves are sometimes deformed, and occasionally cross, although in such spores the membrane is usually wrinkled or otherwise abnormal. The anterior portion of the spore, containing the sporoplasm, capsules and foramina, is relatively stable, varying a little in size, but otherwise similar in all spores. Sixty per cent of the population have angular measurements between 20–32°, and 32–48° and 23–40° for anterior, posterior and tangential angles, respectively. The range for this portion of the population is about that seen in other species.

Discussion. None of the previously described Ceratomyxa have a form very reminiscent of that seen in C. insolita. It evidently is a species which has differentiated in a direction not shared by most of the members of the genus. Nevertheless, the basic architecture is that of the Ceratomyxa, and it seems proper to place it in that genus. The very large capsules with the prominent, unequally elevated foramina are unique. The form has, therefore, been named C. insolita n. sp. It is the first Ceratomyxa to be described from a member of the Cheilodactylidae.

Ceratomyxa gibba n. sp. (Text-fig. 6, Figs. 70–74)

Habitat. This species occurs in the gall bladder of Congiopodus leucopaecilis (Richardson). It is not a very common species, and has been seen in but a single host, in which it was mixed with C. castigata. There was no evidence of irritation of the host organ.

Trophic Stages. The trophozoites are almost indistinguishable from those of C. castigata. Young forms have not been sorted out. The larger, sporulating trophozoites attain a size somewhat larger than C. castigata, reaching a diameter of about 25μ when rounded. They are very transparent, although a little less so than C. castigata, and have a few inconspicuous granules. An occasional small, spherical inclusion, about 0.5–1.0μ in diameter, are found. These are apparently oily in nature. Only disporous trophozoites have been seen.

Spore Dimensions. Breadth, 14.2–18.9μ (17.0μ), height, 5.6–8.0μ (6.9μ), valvular axes, 7.6–15.2μ (10.2μ) and 6.9–10.2μ (8.3μ), capsules, 2.5–3.3μ (2.8μ) by 1.8–2.5μ (2.3μ) and 1.9–2.9μ (2.3μ) by 1.5–2.2μ (2.0μ). Anterior angle, 78–113° (96°); posterior angle, 151–189° (170°), tangential angle, 134–162° (150°) Curvature index, 94°; taper index, 20°; valvular index, 74°. Breadth height ratios for quartiles of breadth range, 2.11, 2.59, 2.42 and 2.35.

Spore Morphology. The curved spore is made up of unequal, different shaped valves and has unequal polar capsules. In sutural view the spore has a convex anterior margin, often curving outward toward the tips of the valves (Fig. 72). The two valves are often different in this respect, as in Fig. 72, although some are seen with both valves curving outwards terminally, when the spore assumes a broader. flatter shape (Fig. 73). One valve is usually larger in diameter than the other, and this tends to give the spore a hump-backed appearance. The valvular tips, on the average, are posterior to the suture. The valvular taper is quite variable, the shorter valves often being quite rounded in shape, while the more elongated.

valves sometimes terminate in quite narrow tips. The suture is much broader in immature spores (Fig. 74). In mature spores it is rather narrow, and slightly elevated. Few spores orient themselves so that a capsular view is obtained. Those seen in capsular view are straight, or nearly so, with the capsules opposite or slightly away from the midline.

The polar capsules are equal to somewhat unequal. They are broadly oval structures, opaque, and situated near the anterior margin of the spore. They open near the midline of the anterior margin by way of very narrow, short necks. Capsulogenous cells are conspicuous in younger spores, and often remain as irregular, basophilic masses associated with the capsulogenous nuclei. The number of coils in the filament could not be counted.

The sporoplasm is relatively large, but does not completely fill the spore cavity. It is variable in position, finely granular in structure, and contains two vesicular nuclei, which are rather small. In most spores several refractive spherules are seen, mostly outside of the sporoplasm itself.

Spore Variability. Variability in this species, other than the usuall differences in spore size itself, centres on the differently shaped spore valves. Some valves are quite stubby, while others are elongated and more curved, while still others are elongated and less curved. Various combinations of valves produce spores with differing outlines, the range of which are suggested by Figs. 70, 72 and 73. Sixty per cent of the population sample measured have anterior, posterior and tangential angles ranging between 88–110°, and 145–162°, respectively. This breadth of the range containing 60% of the population is only moderately greater than that seen in most species, as most of the spores with nearly equal valves do not lie in the median 60%

Discussion.. The only species of Ceratomyxa known from the Congiopodidae is C. castigata, described previously in this report. The two species differ most significantly in size, curvature and valvular taper (13.1μ and 17.0μ, 41° and 94°, 34° and 20°), insofar as the measured parameters are concerned. They are evidently not identical, as C. castigata has been seen in a host with C. gibba, and one without C. gibba. There was an almost perfect agreement in the two hosts of the C. castigata. populations. Of the various species which have been found in the closely allied scorpaenids, none are very similar to C. gibba C. yoichiensis (Fujita, 1923) has spores which are straight, and C. starksi (Jameson, 1929) has symmetrical, larger spores.

The form of the typical spore fits with group II-B-1 or II-C-1, with the majority of spores falling into the latter group. In the former group, C. declivis and C. intexua are similar in breadth, as is C. obovalis (Fatham, 1930) Spore shape excludes C. intexua and C. obovalis at once, the former having straighter, more slender spores, and the latter more oval spores. The spores of C. declivis are only slightly smaller, the various dimensions alone not being sufficient to provide a dependable method of separation. However, the spores of C. declivis are less broad, relatively, and have prominent eosinophilic granules in Giemsa preparations, which are not seen in this species. The slight differences in angular measurements, like those in linear dimensions, are insufficient to provide dependable methods of separation, the means being no more than 5° different. However, the taper index (30° for C. declivis and 20° for C. gibba), which tends to be quite a stable index, seems to be dependably different. Actually, the differences between the two forms, when compared, is considerably greater than the raw data of measurement would suggest, as reference to the figures will show. Of the species in II-C-1, this form most resembles C. flexa It differs from C. flexa in being much less curved (curvature index 131° and 88°), in the inequality of the spore valves, as well as in lacking eosinophilic granules when stained with Giemsa. As this from does not correspond with other named species of Ceratomyxa, it has been designated C. gibba n. sp.

Ceratomyxa gemmaphora n. sp. (Text-fig. 6, Figs. 75–82).

Habitat. This species occurs in the gall bladder of Caesioperca lepidoptera (Bloch and Schn). Only a single host of this species was available for study. It was taken by a trawler working out of Wellington in September, and was heavily infected. The wall of the gall bladder appeared thickened, and the upper part of the gall

bladder and bile duct was red and inflamed. The bile was yellow, and apparently of normal viscosity.

Trophic Stages. The trophozoites are extremely variable in shape and size, ranging from about 3μ to about 40μ in diameter Some are rounded, but the majority have long, slender, tapering pseudopodia, which are only rarely branched. The smallest forms are more frequently rounded but some are actively motile, when they assume a pyriform shape, with a trailing process Larger trophozoites, of about 5–7μ, tend to be more active than the smallest forms. They usually develop one or several small, sharply-pointed pseudopodia anteriorly, moving in the manner described by Davis (1917, p. 207) for a form from Cestracion zygaena.

Ordinarily, a single caudal prolongation is present, although small remnants of the originally anterior pseudopodia are also seen Moving forms often incline the posterior pseudopodium, and without changing direction Occasionally, however, forms with no anterior pseudopodia, and two approximately equal posterior pseudopodia are seen (Fig. 76).

Smaller and larger trophozoites often assume a floating posture. The majority of floating trophozoites are more or less triangular, with two anterior pseudopodia and a long posterior one (Fig. 75). These pseudopodia are often drawn out to a great length, some measuring 150μ from the tips of the anterior and posterior pseudopodia. Floating forms often occur with more than two elongated pseudopodia, sometimes four or five are present extending in different directions. These forms do not exhibit progressive movement, and in the few instances when they were seen to change from floating to motile forms, the pyriform shape was assumed before movement began.

In addition to the motile and floating forms, some clavate individuals were seen This form is not common, apparently, and does not occur in motile individuals In some other. Ceratomyxa the clavate form appears to be used primarily for organisms attached to the wall of the gall bladder.

Except in the pseudopodia, which consist entirely of ectoplasm, the ectoplasm is narrow and difficult to distinguish. It shows no visible structure. The endoplasm is relatively transparent, but less so than the ectoplasm, being shadowed in a finely granular pattern Small, more or less angular inclusions occur in small numbers, and a few larger, refractive spherules, apparently of an oily material, also occur. Nuclei cannot be seen in living organisms, but sporoblasts can be distinguished. The pseudopodia often develop small bleb-like enlargements of homogeneous material.

There is little tendency of the trophozoites to aggregate, although masses of them may be attached to the wall of the gall bladder in the same vicinity, and small groups of floating forms are sometimes entangled together by the pseudopodia. There is no evidence of union between them.

Rounded buds are produced internally. They are eventually released, sometimes in groups of up to five or six. It is not known whether this is a constant feature of this species, or whether the infection was in a state favouring their formation. However, they were quite abundant, more so than in any of the other forms that have been seen. The bud formation is undoubtedly the same phenomenon as that referred to by Davis (1917), who remarked that gemmules represented a common form of reproduction in the Ceratomyxidae.

Spore Dimensions. Based upon the measurement of spores fixed in sublimate acetic, stored in alcohol and measured in water suspension. Breadth, 14.2–23.0μ (19.2μ); height, 5.9–8.3μ (7.0μ), thickness, 5.6–6.6μ (6.4μ); valvular axes, 7.8–13.2μ (10.8μ) and 7.3–12.2μ (9.4μ); capsular diameter, 2.0–3.4μ (2.1μ). Anterior angle, 94–130° (116°); posterior angle, 33°, valvular index, 82°. Breadth height ratios of quartiles of breadth range, 2.37, 2.65, 2.89, and 2.82.

The presence of a few spores considerably more curved than the others resulted in bringing the mean figure somewhat below the medians for the angular measurements. The medians of 128°, 205° and 172° for anterior, posterior, and tangential angles, respectively, more closely describe the average spore.

Spore Morphology. The spore is a broad ellipsoid, flattened to somewhat curved, with subequal valves and relatively small polar capsules. In sutural view the anterior margin is arched, with a slightly inset sutural line. The lateral portions of the valves, in some spores, are slightly flattened anteriorly (Fig. 82). The posterior margin is straight to gently concave, with a few spores having a moderate concavity of the posterior margin. The two valves are equal to sub-equal. but the average difference between them stands at the threshold of dependability. Valvular taper is moderate, and the valvular tips rather broadly rounded. The distinct, elevated suture is straight or nearly so. In capsular view the spore is flattened (Fig. 79) and straight. It is common for one valve to be somewhat narrower than the other in capsular view, giving the spore a tapered appearance This is also evident in slightly flattened spores in permanent preparations (Fig. 80).

The relatively small polar capsules are nearly spherical, and lie near, but not at, the capsular margin of the spore. In capsular view they are opposite or slightly rotated. In immature spores the capsulogenous cells are conspicuous, with large nuclei. The cells disappear entirely as the spores mature, but the nuclei are usually persistent.

The rather large sporoplasm is somewhat granular and alveolar in fresh spores. It does not fill the spore cavity, and may be symmetrical or asymmetrical in its arrangement. In many spores it is drawn out into prolongations which adhere at their tips to the inner surface of the spore membrane (Figs. 80, 82). There are two small, vesicular, sporoplasmic nuclei.

Spore Variability. As with most Ceratomyxa spores, there is some variability in spore curvature, the range being essentially that from the spore shown in Fig. 81 to a curvature a little greater than that shown in Fig. 78. It is not a particularly variable species, 60% of the population having anterior, posterior and tangential angles between 120–30°, 195–212° and 170–175°, respectively.

Discussion. It is curious that no members of the Ceratomyxa have been reported from the Serranidae, although other closely related percomorph fishes are known to harbor several species. Of the species encountered in New Zealand, the rather closely allied Plagiogenion rubiginosus harbors C. flexa. The spores of C. flexa differ from this species in a number of ways, being smaller, more curved, and having eosinophilic granules when stained with Giemsa. C. gibba from Congiopodus leucopaecilis is also about the same size, but has more oval capsules, more unequal valves of a different shape, and is more curved.

The average spore of C. gemmaphora falls near the borderline between groups II-B-1 and I-B-1. Of the species in group II-B-1 C. declivis is significantly smaller, and C. blennius is significantly larger. Of the species between these extremes in the list, C. intexua and C. scatophagi have spores of considerably less height, C. vepallida has spores of greater height, and C. gibba has already been mentioned. C. obovalis (Fantham, 1930) has a range of shapes and sizes, most of which are distinctly smaller than C. gemmaphora, and is generally more Leptotheca-like in appearance. The broader strains are not as high in relation to their breadth, and the smaller strains are significantly smaller. C. lata (Dunkerly, 1921) has more crescentic spores, with larger polar capsules. Of the species in I-B-1, C. castigatoides is significantly smaller, and C. starksi (Jameson, 1929) is significantly larger. Of the remaining species, C. maenae (Georgévitch, 1929) is a bit of a puzzle. It is described as producing microspores and megaspores, a trait which is certainly not seen in this species. If C. maenae should prove to be a mixture of two species, C. gemmaphora is not unlike the larger strain, but appears to differ in not having fusiform sporoblasts No polysporous trophozoites were seen in C. gemmaphora, another trait which Georgévitch gives for C. maenae. It seems quite improbable that C. maenae and this form are the same. C. yoichiensis (Fujita, 1923) has spores which are straight from all views, and also somewhat larger than those from Caesioperca. As this form cannot be equated with any of the previously described species, it has been designated C. gemmaphora n. sp.

Ceratomyxa vepallida n. sp. (Text-figs., 6–7, Figs. 88–92).

Habitat. This species occurs in the gall bladder of Caulopsetta scapha (Forster). It is rather common, having been found in at least five Caulopsetta, taken in winter, spring and summer. It is probably more common than appears superficially as the trophozoites are often present with few spores, and it is probable that it is sometimes present without being noticed. It occurs in combination with various other Ceratomyxa species.

Trophic Stages. The trophozoites are very clear and transparent in life. They are usually attached to the wall of the gall bladder, often in clusters. Unlike most of the Ceratomyxa, attached forms do not tend to develop a clavate shape in most cases, and the attached trophozoites are shaped much like the motile forms. Motility is slow, and the pyriform body has a distinct, but relatively short, posterior process. There are few pseudopodia, slender in shape, with sharp tips. They very rarely branch. The largest forms reach a maximal diameter of about 25μ.

The ectoplasm is clear, transparent, and without inclusions. The endoplasm is also very transparent, and nearly without inclusions. In bright field illumination, a few rather small

inclusions are sometimes seen. These are not highly refractive, and are always inconspicuous In dark contrast phase the nuclei become visible as dark objects, with differing optical densities and some evidence of interior structure, but details of structure cannot be seen. An occasional bright-rimmed inclusion, apparently fatty in nature. is seen In dark field illumination the trophozoites are almost invisible, except for the bright outline of the plasmalemma, and the outline of any sporoblasts which may be present. The transparency of the trophozoites, and their lack of visible differentiation in dark field illumination make these trophozoites easy to recognize in mixed infections.

Trophozoites containing sporoblasts are easily recognized. They are round to oval, and are easily seen in bright field, dark field, or phase illumination. All sporulating forms have been disporous (Fig. 88). In some instances a portion of the endoplasm is more highly basophilic in haematoxylin mounts, retaining the stain after the remainder of the protoplasm is destained.

Spore Dimensions. Based on small samples of spores from four hosts Breadth, 16.0–21.4μ (18.7μ); height, 7.8–9.6μ) (8.6μ); thickness about 8.1μ; valvular axes, 8.8–11.6μ (10.4μ), and 7.8–10.4μ (9.2μ), capsules, 2.9–3.6μ (3.2μ) by 2.5–3.2μ (2.9μ) Anterior angle, 94–117° (104°), posterior angle, 177–215° (194°); tangential angle, 142–180° (158°) Curvature index, 62°; taper index, 44°; valvular index, 90°. Mean breadth: height ratios for quartiles of breadth range, 1.88, 2.04, 2.26, and 2.30.

Spore Morphology. Despite its common occurrence, most hosts contain very few mature spores. As spores do not mature well in depressions, relatively few are seen, and as a result dimensions are based on a series of small samples, as are the observations on spore morphology In all, however, several hundreds of spores have been examined.

The small spore has rather stubby valves, equal to subequal in length, and terminating in broadly rounded tips. In sutural view the spores have a convex anterior margin, not interrupted at the suture and a posterior margin varying from flattened to moderately concave. The broadly rounded valvular tips are turned toward the posterior margin, in most spores. The two valves are usually nearly equal. They meet in a somewhat elevated suture, which is sometimes slightly oblique in its course. In capsular view the spore is straight or somewhat curved (Fig. 91). As in a number of other species of Ceratomyxa, the curvature of the spore is about equal in sutural and capsular views. The measurement of a small sample of 6 spores for horizontal angles resulted in means of 105°, 195° and 165° for the convex angle, concave angle, and horizontal tangential angle, respectively. These values are essentially similar to those found in the angles measured in sutural view.

The capsules are somewhat variable in size, but are usually equal. Seen in capsular view they are opposite in position, or slightly rotated. In sutural view they are placed near, but not at, the anterior margin of the spore. They are broadly oval, with sharply narrowed necks. The filament cannot be seen in fresh spores. In immature spores, the capsulogenous cells are large and distinct (Fig. 90), but in mature spores the capsulogenous nuclei are usually missing.

The sporoplasm is usually more or less central in position. It contains a number of small inclusions, some of which are quite refractive, and two vesicular nuclei usually lying close together. The sporoplasm fills but a small part of the spore cavity, and in the space between the sporoplasm and the spore membrance, a variable number of refractive spherules of apparently an oily nature are usually visible.

Where trophozoites have disintegrated, spores are sometimes seen surrounded by membranous remnants, apparently of the sporoblast (Fig. 90). This is not uncommon in Ceraiomyxa from flat-fishes, and sometimes appears to add to the variety of shapes that the spores assume unless care is exercised. Triad spores are sometimes seen (Fig 92), especially in samples taken in the winter months.

Discussion. This species falls into group II-B-1, with some of the spores approaching I-B-1 and II-A-1. The species in II-B-1 of simar breadth are C. gemmaphora, C. lata, and C. scatophagi C. gemmaphora is broader in relation to its height, and has trophozoites which are somewhat different, especially in the smaller size range C. scatophagi (Chakravarty, 1943), also, has spores with a considerably lesser height, as well as somewhat greater breadth C. lata, which occurs in Pleuronectes microcephalus (Dunkerly, 1921), has spores of the same breadth but somewhat less in height (19x7μ). It is somewhat more crescentic in shape. It seems certain that the form from Caulopsetta is closely related to C. lata. It is quite possible that when more information is available concerning the variability of the spore in size as well as shape, and the trophozoite of C. lata has been found, the two may be found to be identical. There seems to be too little evidence to make a positive identification, however. The spores in the New Zealand material which are about 19μ in breadth have a height of about 8.3μ, on the average. This is a greater difference in breadth height ratio that can ordinarily be expected in two.

samples belonging to the same species, according to the results obtained here, and it is tentatively concluded that the two forms are not identical. No other species in the bordering groups are very closely related to this species in the morphological sense. As the form has not been identified as belonging to previously described species, the name C. vepallida n. sp. has been given to it.

Ceratomyxa subtilis n. sp. (Text-fig. 6, Figs. 83–87).

Habitat. This species occurs in the gall bladder of Coelorhynchus australis (Richardson). It is not a very common species, having been found in a single host taken in the Wellington area in August, as a heavy infection, and in another taken in December as a very light infection. There was no evidence of abnormality in the host organ.

Trophic Stages. No trophozoites were seen in the two hosts in which spores were found Trophozoites were seen in but a single host, and in this case no spores were seen. It is probable that these were trophozoites of C. subtilis.

The trophozoites are slenderly pyriform, with a long posterior process terminating in a region of clear ectoplasm. The endoplasm is clear and transparent, containing a large number of rounded, inconspicuous inclusions, about 1 2μ in diameter. The inclusions tend to appear in a linear arrangement in the posterior portion of the body. The larges trophozoites measured about 25μ in diameter, and were not mature. No sporoblasts were seen.

Spore Dimensions. Breadth, 15.7–26.0μ (21.5μ); height, 3.4–4.5μ (3.9μ), thickness, 3.9–4.5μ (4.3μ), valvular axes, 7.8–14.2μ (11.9μ) and 6.8–12.2μ (10.4μ), capsules, 1.5–2.0μ (1.8μ). Anterior angle, 68–150° (128°); posterior angle, 99–183° (164°), tangential angle, 98–180° (158°) Curvature index, 68°, taper index, 6°, valvular index, 36°. Breadth: height ratios for quartiles of breadth range, 3.94, 5.37, 5.20 and 6.57.

Spore Morphology. The rather small, slender spore has equal to unequal valves, terminating in narrow, rounded tips. In sutural view the anterior margin is convex, with a rather regular curvature, either without interruption or with a very slight constriction at the suture. The straightest spores have the anterior margin of each valve nearly flat, and meeting at a rounded angle at the suture (Fig. 84). The posterior margin is nearly straight in the least curved spores, and distinctly concave in the more arcuate forms (Fig. 85). Although the position of the valvular tips is quite variable, it is generally somewhat below the end of the suture (posterior angle, 164°). The two valves may be equal or somewhat unequal (Fig. 84). They may be similar in shape, or one valve may be somewhat more curved than the other (Fig. 83). There is very little gradient of taper, but the spore height is so small that the valves terminate in quite narrowly rounded tips In capsular view, the spore may be straight slightly sigmoid, or somewhat bent. The spore tends to be slightly flattened horizontally, with the thickness a little in excess of the height.

The relatively small polar capsules lie near the anterior margin, through which they open. They are oval, with narrow necks, and converge on the suture, quite sharply in fixed and stained spores (Fig. 87). The filament cannot be seen in fresh spores. Capsulogenous nuclei are usually missing in mature spores.

The small sporoplasm is placed in the centre of the spore, sometimes extending but a short distance beyond the capsules, and sometimes extending nearly half-way along the valves. It is finely granular in fresh spores, and contains a number of very small inclusions, about 0.5μ or less in diameter, which are tinted by Bismarck brown, but not by methyl green. They disappear in fixed and stained spores. There are two small, vesicular nuclei.

Spore Variability. The spores of this species are quite variable in curvature. The extremes of curvature are approximately those shown in Figs. 84 and 85 Spore breadth is also variable, partly because of differences in curvature, and partly because of differences in valvular length. The relative sizes of the two spore valves are also variable Sixty per cent of the spores have a breadth between 20.0 and 23.9μ, and angular measurements of 120–138°, 150–178°, and 148–171° for anterior, posterior and tangential angles, respectively This range of angular measurements for the median 60% of the spore population is rather wider than for most species.

Discussion. No Ceratomyxa have been previously reported from the Macrundae. The typical spore form places this species in group II-C-1. Only C. lunata, of the previously described species, is similar in breadth. This form, however, is much more curved, and broader at the suture, with a height of 7–9μ (Davis, 1917). While there are a number of species with a slender spore form, all of these are much larger than C. subtilis, except for C. agglomerata, C. pallida and C. truncata Until.

C. pallida has been recovered and more fully described, it will be most difficult to recognize. According to Thélohan (1895), the trophozoite is 16–20μ in diameter, somewhat smaller than those seen in Coelorhynchus, and apparently without the inclusions which occur in the Coelorhynchus form. The spore is somewhat higher, also, and considerably greater in breadth. C. truncata appears to be significantly larger, and has much broader valvular tips (Thélohan, 1895) C. agglomerata is somewhat larger in all dimensions, with the sporoplasm very asymmetrically placed in most spores (Davis, 1917), and a very marked disparity in valvular shape. It is concluded that this form is previously undescribed, and it has been designated.

C. subtilis n. sp.

Ceratomyxa hama n. sp. (Text-fig. 7, Figs. 93–7).

Habitat. This species occurs in the gall bladder of Caulopsetta scapha. (Forster). It is one of the most common of the Ceratomyxa occurring in its host, and is found all year round. It usually occurs in combination with other Ceratomyxa, but was seen alone in one host. It does not cause any visible abnormality in the host organ. It has been seen in fishes taken in the Wellington and Napier region.

Trophic Stages. Good trophozoites were not available in the only host containing only.

C. hama, and since there is generally a confusing mixture of species present, it is only with the greatest difficult that they can be sorted out. The problem is made more complex because there are several species of about the same size, with curved spores, difficult to distinguish in the immature state while still in the trophozoite As several of the types of trophozoites are quite distinctive in appearance, it would be valuable to make a much more thorough study of the.

Ceratomyxa fauna of Caulopsetta scapha. The trophozoite which is believed to belong to this species has been recognized, primarily, by a comparison of the frequency of mature spores of three types which occurred together so often, and a comparison of the frequency of the spores.

The trophozoites are relatively large some reaching a length of 125μ when extended, although rounded forms are much smaller. They have a tendency to occur in two different forms, a motile form and an attached form. The motile form is a modified pyriform shape, usually with a definitely enlarged region, in which any spores that are present occur (Fig. 93). The protoplasm extends backward in a large, elongated region, rather like the posterior process of smaller Ceratomyxa species, although so much larger in size. The shape gives the effect of clavateness rather than that of a pyriform organism, because of the large quantity of protoplasm in the trailing portion Movements are never fast, and many trophozoites appear not to move at all.

Attached trophozoites are clavate, usually with an enlarged region containing any developing sporoblasts. They are attached by one or several short, slender, tapering pseudopodia at one end. The elongated portion of the body is usually gently curved, and extends outward into the bile. At the free end of the trophozoite one or several slender pseudopodia may be present.

A common phenomenon is the presence of three or four enlargements on the pseudopodia. These enlargements are quite distinct, and are about the size of the smallest trophozoites. It is thought that they are buds, for the production of new individuals.

The ectoplasm is transparent, and without inclusions. It is without structure in bright field, dark field, or phase contrast. The endoplasm is also quite transparent in bright field illumination. It contains two kinds of inclusions, in addition to nuclei and developing sporoblasts. The most numerous inclusions are indistinct, spherical bodies, about 1.0–1.25μ in diameter. These occur in large numbers in mature trophozoites. They are not highly refractive and are rather inconspicuous despite their large numbers. They are much more conspicuous in dark contrast phase, where they appear as dark bodies. They cannot be seen in dark field. They often occur in rather regular lines in the elongated portion of the trophozoite. They are persistent in fixed and stained slides, even surviving the Feulgen technique. In permanent preparations they are coloured by the acidic dye. Among these inclusions there is a small, variable number of irregular dark granules. They are brownish in colour, and usually less than 0.4μ in diameter In smaller trophozoites they occur in very small numbers, about 5 to 7 of then being the usual complement. As the sporoblasts appear and develop, they become a little more abundant, but are never a very conspicuous portion of the endoplasm. These granules appear as bright objects in dark field illumination. Their presence makes it possible to distinguish the trophozoites from C. vepallida, which lacks them, and C. laxa, which has a great abundance of them.

The trophozoites are monosporous or disporous. No polysporous forms have ever been encountered. In this respect they differ from the trophozoites of C. laxa, which are sometimes polysporous.

Spore Dimensions. Based on spore samples from three hosts. Breadth, 18.5–29.8μ (23.4μ), height, 6.8–8.3μ (7.4μ), thickness, 7.0–8.3μ (7.7μ), valvular axes, 9.3–17.5μ (14.4μ) and 8.3–16 1μ (11.9μ); capsules, 2.0–3.5μ (3.2μ). Anterior angle, 59–117° (101°); posterior angle, 107–205° (160°); tangential angle, 98–179° (136°) Curvature index, 99°, taper index, 24°; valvular index, 59°. Convex angle, 63–113° (91°), concave angle, 103–179° (139°), tangential angle, 89–152° (111°). Bending index, 130°, horizontal taper index, 28°, valvular index, 48°. Breadth height ratios for quartiles of breadth range, 2.57, 3.04, 3.46, and 4.08.

Spore Morphology The thin-walled spore is curved, bent, or both curved and bent. The anterior margin is convex, gently or sharply, depending on spore curvature, and the posterior margin flattened or concave, again depending on the direction and sharpness of spore curvature (Figs. 100–102). The valves in the majority of spores are similar in shape although often slightly unequal in length In some spores, however, one valves is more inflated. and the other terminates in a narrower tip (Fig. 94). The two valves meet in a straight suture, slightly elevated, and rather narrow. Because of the variety of curvatures affecting the spore, the overall spore shape is extremely variable In spores with a curvature in both directions, the essentially spiral shape can be seen when seen in valvular view.

The capsules are nearly spherical, but narrow sharply as they approach the anterior margin, through which they open. They converge sharply on the suture. In fixed and stained preparations the capsules are more pyriform in shape. The filament is easily seen in the capsules of fresh spores, making from four to six coils. When extruded, the filament reaches a maximal length of about 60μ. Capsulogenous nuclei are usually persistent in stained spores (Fig. 102).

The sporoplasm is fairly large, and may be symmetrical in position or placed far off centre, nearly all occurring in one valve. It is finely granular, and contains a few refractive spherules. The spore cavity usually contains a few oily spherules. When spores are first exposed to neutral red in depression slides, the spherules are not stained. During the first 24 hours they grow, and become deeply tinted with the dye. After about two more days, the colour begins to fade In a week or so the large spherules break down into many smaller ones, and the sporoplasm is noticeably smaller in size. It would appear, therefore, that some metabolic activity goes on in the spores. At the end of a month, many spores have no sporoplasm left at all, although the spore shape is still maintained by the membrane, while others have a small, rounded mass of sporoplasm containing one or two nuclei Still others, apparently having died earlier, have large sporoplasms in which changes in refractivity have occurred.

Spores stained in Giemsa (Fig. 99), contain a number of bodies which are deeply stained with eosin. These are, in some ways, similar to those seen in C. declivis, C. flexa and C. arcuata, but differ in that they can be seen, if indistinctly, in permanent mounts stained with haematoxylin (Fig. 102), as well as in having a quite different form. While some small, rounded or irregular bodies occur, in each spore there are one or two centres about which the material tends to be disposed. These are placed laterally usually beyond the end of the sporoplasm. Similar bodies are sometimes seen in spores of C. laxa (Fig. 104), although they are less conspicuous in that species In mature spores, the main centres of the eosinophilic material tend to disperse, and the substance is dispersed in the spore cavity. Here it forms more or less filamentous structures, often spiral in form, as well as amorphous masses. The spiral form of some of the inclusions is very evident. No conclusions have been drawn concerning the nature of this material.

Spore Variability. There is a very extensive variability of the spores of this species largely associated with the amount and direction of spore curvature. With the wide range of spore shapes resulting from the variable curvature, as well as the occurrence of somewhat similar curved species of about the same size, difficulties are constantly encountered in orientation of spores and in being sure that no errors are made in placing them in the appropriate categories. As a result, it is felt that the measurements, particularly of angles, are somewhat less dependable in this species than in most. As a result, no extensive analysis of variation has been undertaken.

Despite all of the difficulties, however, the measurements recorded proved to be relatively reproducible. In two hosts containing large numbers of spores of this species. and in which neither C. torquata nor C. laxa were seen, and in which more confidence can be felt in the samples the two samples had identical breadths, mean height and thickness within 0.1μ mean valvular axes differing by 0.5 and 0.1μ, and capsules differing by 0.4μ in diameter. Differences in anterior. posterior and tangential angles were 6°, 7° and 1° in the two samples. while differences in means of convex. concave and horizontal tangential angles were 16° 15° and 12°. Other smaller samples, taken from hosts containing more different species and in which more possibility of error occurred matched less well but differences were not greater than those found in other curved species of Ceratomyxa. Despite these results however, the impression

was gained that the consistency of angular measurement was more a matter of chance than of accuracy in measurements, and that errors in spore orientation were more or less comparable in the various samples measured. Where spores may be both curved and bent, or either curved or bent, the angular measurements are much more difficult to take, and the technique yields results in which one feels rather less confidence. Perhaps the most definite statement that can be made is that about the same range of sizes and shapes were seen in each infected host, and that there was no evidence of a greater frequency of any kind of shape in one sample, as compared to another, as might be anticipated if the differences in spore shape were characteristic of different strains.

There are many species of Ceratomyxa reported in various species of flat-fishes. Over 20 have been described previously from different localities. It is not impossible that these forms, like limpets and some other animals, have a tendency to occur as local species, with relatively restricted geographical distribution areas. In general, there seems to be a strong tendency for the species to be restricted to flat-fishes, but little tendency toward a host specificity within the flat-fish group. It is also possible that we are dealing with a much smaller number of extremely variable species. At the present time there is insufficient evidence to make firm conclusions possible.

In the New Zealand material, there has been difficulty in sorting out the spores found in Caulopsetta scapha into meaningful categories which showed any consistency. It seems that there are several rather variable strains, all having curved spores of about the same breadth, forming a complex which is most confusing. As spores are sorted out into categories, it is found that it is quite easy to have more categories than species, and, perhaps, no less easy to have more species than categories. Eventually, a set of categories was developed which appeared to more or less consistently provide places for the spores that were seen, and to correspond to the trophic stages which were also seen, and some degree of confidence in those categories developed. It is, neverthless, possible that there are more than the number of species recorded. Fujita (1923), found material indicating that truncations of the valvular tips, and directions of spore curvature provided dependable criteria for species groupings. In the New Zealand species, the attempt to include valvular truncation in the categories resulted in considerable confusion, and would have required at least three more species groups, which were always associated with other species, so this criterion was not used. Direction of curvature, also, appeared to be independable in this species, as spores with essentially similar valves exhibited horizontal, vertical and combined curvatures. and appeared always to occur together. It is true, however, that much more constant species groups could be described if the horizontally, vertically, and doubly curved spores were separated into different species. On two bases, I am inclined to have no faith in this kind of distinction in the material from Caulopsetta. The three types of spores occur again and again in combination, and, in addition, there is a certain similarity in the angular measurements of spores seen in sutural and valvular views. Thus the means for the three angles measured in sutural view were, 101°, 160° and 136° and the three measured in capsular view were 91°, 139°, and 111°. These values are similar, as if the spores tended to be bent about 10–15° more in capsular than in sutural view. It has been noticed that when spores are bent in both sutural and capsular views, there is a tendency for the angular measurements to be similar in the two views, as if the factors resulting in spore curvature acted independently of those determining capsular position.

Discussion. The spores of this species fall into group II-B-1, with some spores having so little valvular taper that they fall in II-A-1. In the latter group.

C. arcuata is most similar in breadth, but differs in having spores which are more slender. In II-B-1, C. truncata, C. elegans, C. constricta, C. moenei, and C. amorpha are similar in spore breadth, as well as C. laxa and C. torquata, to be described subsequently from Caulopsetta. In none of these species is the spore both curved and bent as in this one. While some of Fujita's (1923) species from Japanese flat-fishes have somewhat similar form, none are as small as this species. It may be that if clines can be shown connecting the Japanese forms with those from New Zealand, and resulting in a consistent change of size, some may prove to be identical with the New Zealand species, but the difference in size is much too great to permit their being considered identical without such evidence. It must, therefore, be concluded that this species is not previously described, and it has been named C. hama n. sp.

Ceratomyxa laxa n. sp. (Text-figs. 7–8, Figs. 98, 103–107)

Habitat This species occurrs in the gall bladder of Caulopsetta scapha (Forster). It is relatively common, particularly during the warmer months, and has been seen in at least seven Caulopsetta, taken by trawlers in the Wellington area. There is no evidence of abnormality in the host organ.

Trophic Stages. Motile trophozoites of this species have not seen seen, even in cases where other trophozoites were in fairly rapid motion. Most of them are attached to the wall of the bladder, or float freely in the bile. Attached forms are sometimes nearly clavate, but the majority of trophozoites are essentially oblong in form, with prominent, branching pseudopodia. In attached forms, slender pseudopodia are often thrust between the host cells. In floating forms, pseudopodia tend to be formed over most of the body surface, and extend outward in all directions (Fig. 98). They sometimes branch, and it is not uncommon to see a small tuft of delicate, needle-like pseudopodia at the end of a larger pseudopod.

The clear, transparent ectoplasm is without inclusions, and forms a continuous zone about the body. The endoplasm is highly granular, and darkened by hundreds of small, irregular, brown bodies which mask the remaining inclusions, and make it easy to recognize the trophozoite in mixed infections. In both dark field and dark contrast phase illumination, the granules appear as bright bodies. They are similar in colour and general appearance to the granules seen in C. hama, but are much more numerous. Among the granules, but usually obscured by them, are a few spherical inclusions, appearing as white-rimmed bodies in dark contrast phase and in dark field. These are apparently fatty in nature, and disappear in permanent slides, while the granules persist. The nuclei, which cannot be seen in dark field or bright field illumination, can be seen in dark contrast phase. They are difficult to make out because of the masking effect of the granular inclusions.

Sporoblasts and developing spores are conspicuous, and as they lack the granular material, appear as lighter areas. In the majority of trophozoites from two to eight spores are formed. An occasional unisporous form is also seen This is the only polysporous species that has been observed in Caulopsetta. The largest trophozoites reach a length of about 80μ, not including the pseudopodia. The pseudopodia are often very long, reaching a maximum length about equal to that of the body mass.

Spore Dimensions. Based on samples from two hosts. Breadth, 20.8–30.3μ (25.6μ), thickness, 7.8–9.8μ (8.7μ), valvular axes, 9.8–19.0μ (15.7μ) and 8.2–15.6μ (14.5μ), capsules 2.9–3.9μ (3.4μ) Convex angle, 60–116° (88°), concave angle, 103–204° (147°); horizontal tangential angle, 93–173° (130°). Bending index, 125°; taper index, 17°; valvular index, 59°. Breadth thickness ratios for quartiles of breadth range, 2.50, 2.80, 3.22, 3.54.

Spore Morphology. The spore is bent, with relatively large, round polar capsules, and is flattened horizontally. Seen in capsular view, one border is convex, sometimes with a slight constriction near the suture (Fig. 105), and sometimes passing the suture without interruption (Fig. 103) The two valves are broad at the suture, and taper moderately to rather broadly rounded tips, in most spores, but are rather stubby in others, terminating in very rounded tips. The principal variability appears to be in the length of the valvular axes, some spores having much longer valves than others, relatively speaking. The extent of variability is about that indicated in Figs.105 and 104. The two valves are equal to distinctly unequal in axial length, and meet in a prominent, straight suture. In sutural view, which is seen but rarely, the spore is flattened, with a straight or slightly curved axis.

The two capsules are round, nearly spherical, and with short, narrow, inconspicuous necks. The filament is prominent in life, and is coiled about five or six times, insofar as could be seen in the few spores seen in sutural view. The capsules sometimes converge somewhat on the suture, and are sometimes slightly rotated. While the capsulogenous nuclei are sometimes seen in stained spores, they are not usually persistent. There is no remnant of the capsulogenous cells in mature spores. The filament, when extruded, extends up to about 55μ in length.

The sporoplasm is relatively large, and is usually somewhat asymmetrical in position. It is quite transparent, showing a finely granular structure. It contains a few refractive spherules in fresh spores, usually small in number and in size (Fig. 103). These disappear in permanent preparations. The two nuclei are vesicular, and usually placed close together. As spores age in depressions, the sporoplasm shrinks in size, and tends to form a spherical mass located in one valve.

Spores stained in Giemsa have a small amount of eosinophilic material, usually in two centres, located near the end of the sporoplasm in each valve (Fig. 104). This material is much less abundant than in C. hama, but is evidently of a similar nature, and tends to form spiral filaments as it disperses.

Spore Variability. While the spores have been seen in a number of hosts, they were usually mixed with other species, particularly C. hama and C. torquata, so that measurement was deemed likely to include spores of other species as well as this one. In the two hosts in which spore identification could be most certain, and in which relatively heavy infections occured, the samples proved to differ somewhat in linear dimensions, but to have very similar angular measurements. The two samples differed by 3.6μ in spore breadth, 0.2μ in spore thickness, and the valvular axes differed by 2.3μ and 1.4μ The differences were occasioned,

primarily, by the occurrence of a larger number of spores in one sample in which the valves were longer, and somewhat more tapered. The capsules were identical in size. The convex, concave, and horizontal angular measurements differed by 4°, 2° and 5° respectively. While the smaller samples measured in other hosts differed in the means from the two larger, more dependable samples, all were between the extremes set by the two larger samples insofar as linear measurements are concerned, and while the angular measurements were somewhat more variable, the spores all fell within the extremes set by the larger samples, and had means within 15° of those seen in the larger samples. It would appear, therefore, that this species varies primarily in valvular length, and that differences in angular measurements are, on the whole, relatively slight insofar as means are concerned.

Discussion. Of the various species of Ceratomyxa occurring in flat-fishes, this species is most like C. hama and C. torquata. Until it is understood that this species is horizontally flattened, whereas the other two are nearly circular in cross section, it is most difficult to sort them out, at least under lower magnifications. Like C. hama, C. laxa falls into a size range which is well below the species found by Fujita (1923) in Japanese flat-fishes, except for C. toitae. C. toitae, however, has spores which are much larger at the sutural line, measuring 13μ in sutural diameter, and has small capsules, 2μ in diameter, with filaments but 20μ in length.

This species falls into group II-B-1. None of the species in its general size range is bent rather than curved, except C. torquata, from which it differs in its horizontal flattening, and in its straight suture. It is concluded that it is a previously undescribed species, and has been given the name C. laxa n. sp.

Ceratomyxa arcuata Thélohan (Text-Fig. 8, Figs. 108–110)

Habitat. This species occurred as a light infection in one specimen of Anthias pulchellas. The host fish was taken by a trawler working out of Wellington in July. Two other Anthias taken at the same time were not infected. There was no evidence of damage to the host organ.

Trophic Stages. These have not been seen.

Spore Dimensions. Based on spores from permanent slides, after fixation in sublimate acetic, and staining in haematoxylin or Giemsa. Breadth, 16.2–36.7μ (25.6μ); height, 4.5–7.8μ (5.7μ); thickness, 5.4–5.9μ (5.7μ); valvular axes, 13.2–24.4μ (18.8μ) and 10.3–21.1μ (15.0μ); capsules, 1.5–2.4μ (1.9μ). Anterior angle, 45–90° (74°); posterior angle, 63–115° (99°); tangential angle, 62–112° (96°). Curvature index, 187°; taper index 3°; valvular index, 25°. Breadth height ratios of quartiles of breadth range 3.34, 3.75, 5.40 and 5.33. Only a small sample of spores were measured for thickness.

Spore Morphology. The slender, arcuate spore has small polar capsules and rounded valvular tips. In sutural view the anterior margin is strongly convex, and the posterior margin strongly concave (Fig. 108). A very moderate valvular taper is present, and the valves terminate in relatively broad to somewhat narrow valvular tips. In some spores, the lateral extremity of the valve is slightly inflected toward the anterior margin, breaking the otherwise smooth curvatures of anterior and posterior margins (Fig. 108). While the two valves are equal in some spores, they are often quite unequal in length, with a mean difference of over 3μ in axial length. They meet in a suture which is scarcely elevated, and is inconspicuous in stained slides.

The polar capsules are quite small, somewhat oval in shape, averaging about 0.1–0.2μ less in breadth than in length. They are somewhat convergent on the suture. In capsular view, they are opposite (Fig. 109). The capsulogenous nuclei are usually persistent, and in many spores remnants of the capsulogenous cells can also be seen.

The fairly large sporoplasm is usually centrally placed, and is quite transparent in fresh spores. It contains two nuclei with rather conspicuous endosomes.

The spores contain a number of eosinophilic bodies which are deeply stained in Giemsa (Fig. 110). These are essentially like those seen in C. declivis and C. flexa, being generally distributed in the spore, and not showing the spiralled form seen in C. laxa and C. hama. They tend to be somewhat larger than those seen in C. declivis, and to be more frequently located in the sporoplasm.

Discussion.. In size and shape this species is very like C. arcuata. While Thélohan (1895) refers to the valves as being of equal length, Parisi (1912) figures spores with as much difference in valvular length as seen in the New Zealand.

material. Parisi also shows spores with a tendency to be curved outward at the lateral extremities of the valves.

Lateral appendages were not seen in spores from Anthias. They may or may not be present in C. arcuata. Judging by Parisi's sketches, the agreement in shape is as nearly perfect as the agreement in size.

While C. arcuata has not been found in members of the Serranidae, it has been reported from the Moronidae by Dunkerly (1921), who observed it in Roccus labrax. It seems highly probable that the New Zealand form is identical with the strains that have been described as C. arcuata.

Ceratomyxa constricta n. sp. (Text-Figs.8–9, Figs.111–115)

Habitat. This species occurs in the gall bladder of Centriscops humerosus (Richardson). It is apparently not a common parasite, having been found in but one of six fishes examined. The infected fish was taken by a trawler working out of Wellington in August. There was no evidence of damage to the host organ.

Trophic Stages. These are unknown.

Spore Dimensions. Breadth, 23.6–29.3μ (26.9μ); height, 5.6–9.0μ (8.1μ); valvular axes, 13.5–15.8μ (14.7μ); and 11.9–15.2μ (13.7μ); capsules, 2.8–3.9μ (3.5μ); by 2.8–3.4μ (3.2μ); Anterior angle, 105–131° (113°); posterior angle, 150–193° (178°); tangential angle, 128–169° (145°); Curvature index, 69°, taper index, 33°; valvular index, 65°. Breadth: height ratios for quartiles of breadth range, 2.88, 3.12, 3.68 and 3.54.

Spore Morphology. The rather plump, slightly curved spores have approximately equal valves with a definite medial constriction in which the suture lies. In sutural veiw the anterior margin is gently convex, forming a continuous curve broken only by the sutural constriction. The posterior margin of each valve is flattened or slightly convex, but the two valves meet at an obtuse angle at the suture (Fig. 114). The valves are nearly equal in axial length, and taper very moderately to broadly rounded tips. They meet in a prominent, narrow, elevated suture. In capsular view the spore is straight or somewhat curved. In a few spores the valves are bent in opposite directions, so that the spore has a slightly sigmoid shape in capsular view.

The capsules are nearly spherical, with very short, inconspicuous necks. They are placed close to the suture, often touching each other. They are usually flattened at the point of contact. In capsular view they are opposite. They converge slightly on the suture. The filament is not conspicuous, but four or five coils may be seen in fresh spores. Capsulogenous nuclei are usually persistent, and lie near the base of the capsules.

The sporoplasm is fairly large, and arranged either symmetrically or asymmetrically. It is quite transparent, but contains a few refractive spherules as well as two vesicular nuclei, with prominent endosomes. The space between sporoplasm and spore membrance usually contains a few refractive spherules, which disappear during the preparation of permanent slides.

Spore Variability. The spores of this species are not particularly variable, the principal differences being in the amount of bending of the spore as seen in capsular view, and the spore height. There is quite a significant difference between the spore height at the two extremes, the range being approximately that shown in Figs. 113 and 114. There are no apparent relationships between the spore height and amount of curvature seen in capsular view. For the angular measurements, 60% of the spore population fell between 106–121°, 165–185° and 136–158° for anterior, posterior and tangential angles, respectively.

Discussion. No Myxosporidia have been reported from members of the Macrorhamphosidae, or, for that matter, from members of the Order Aulostomi. The form of the spore is such that it falls in group II-A-1 or II-B-1, depending on valvular taper. Of the species in the former group, C. intexua is significantly smaller, and C. hopkinsi significantly larger. C. arcuata and C. hama differ from this species in being more slender and more curved, and C. torquata has a sinuous sutural line. C. crassa (Jameson, 1929) has similar dimensions, but the spore has less valvular taper and lacks the medial constriction in the sutural area. Of the species in group II-B-1, C. scatophagi (Chakravarty, 1943) appears to be significantly smaller, and C. moenei significantly larger, insofar as breadth is concerned. Most of the species occurring between these extremes may be eliminated on the basis of the degree of spore bending. Of those remaining, C. monospora has more taper to its valves, and the valves are dissimilar in shape (Davis, 1917). C. undulata

(Davis, 1917) has more slender spores, with narrower valvular tips C. elegans (Jameson, 1929) has spores without a medial constriction, and with a less angled posterior margin, as well as valves of somewhat differing shape. Since it is not possible to equate this form with any of the previously described species, it has been given the name C. constricta n. sp.

Ceratomyxa torquata n. sp. (Text-Fig. 9, Figs. 116–7)

Habitat. This species occurs in the gall bladder of Caulopsetta scapha (Forster). It is not uncommon, having been seen in at least five Caulopsetta. It apparently occurs throughout the year, although rather more of it has been seen in the summer months. No evidence of damage to the host organ has been observed.

Trophic Stages. The trophozoites have not been accurately separated from those of C. hama, which they very closely resemble. It appears that they may have rather fewer of the brownish granules than the trophozoites of C. hama in organisms of the same size, but distinctions between them are most difficult to observe.

Spore Dimensions. Based on a full sample from one host, and small samples from three other hosts Breadth, 20.5–30.3μ (26.9μ); height, 7.8–9.5μ (8.1μ); thickness, 8.3–10.1μ (9.2μ); valvular axes, 14.0–22.6μ (16.7μ); and 10.8–18.0μ (14.4μ); capsules, 2.8–4.7μ (3.8μ); Anterior angle, 85–134° (99°); posterior angle, 126–207° (151°); tangential angle, 115–178° (135°). Curvature index, 110°; taper index, 16°; valvular index, 52°. Convex angle, 64–116° (91°), concave angle, 103–204° (148°), horizontal tangential angle, 95–173° (133°); Bending index, 121°; taper index, 15°; valvular index, 57° Breadth height ratios for quartiles of breadth range, 2.54, 2.97, 3.41 and 3.76.

Spore Morphology. The thin-walled spores are usually bent more than curved, and have nearly equal valves meeting in a sinuous suture. Spores are more often seen in capsular view, as they are slightly flattened horizontally, but as the valves often curve in different directions, it is somewhat difficult to specify spore orientations with accuracy. In the spore shown in Fig. 116, the valve at the right is lying horizontally, while the valve at the left is curving downwards. Seen in valvular view, as one focuses along the length of the spore, the valves tend to follow a spiral course in their curvature. The end result is that one tends to see one valve from a capsular aspect, and the other from a sutural aspect, as it were, so that one valve tends to be somewhat narrower than the other. The two valves meet in a conspicuous, rather narrow, elevated suture which takes a sinuous course. In stained slides, the suture often appears as a double line, but this cannot ordinarily be seen in fresh spores (Fig. 117).

The capsules are nearly spherical, with a narrow neck region. They lie near the suture, sometimes touching, and flattened at the point of contact. In some spores the capsules are somewhat rotated, but in most they are opposite. They converge very little on the suture. Capsulogenous nuclei are usually missing in mature spores. The filament is conspicuous in fresh spores and forms about five or six coils. It reaches a maximal length of about 60μ when extruded.

The sporoplasm is rather large, and variously situated in the spore. It is finely granular, containing a few small inclusions, and usually several inly droplets lie outside of the sporoplasm, between its margin and the spore membrane. These react to neutral red, and show changes like those recorded for C. hama. The two sporoplasmic nuclei, usually placed close together are vesicular, and contain rather prominent peripheral chromatin.

Spore Variability. There is considerable variability in the extent of spore curvature, and in the extent to which the valves extend in opposite directions in their curvature. The difficulty of obtaining satisfactory spore orientation for the measurement of angular dimensions makes it uncertain whether they are accurate representations of the spore shape. On the whole, there was good agreement between the smaller samples and the full sample, with means for the angular measurements within about 15°.

Discussion. The spores of this species fall in groups II-A-1 or II-B-1, depending on the amount of valvular taper, the majority belonging in the latter group. In general size and shape of the spore, this species is far more like C. hama and C. laxa than like other species from other regions of the world. It differs from C. hama in being somewhat less slender at the suture, and in having a sinuous suture. It differs from C. laxa in having much less flattening of the spore in the horizontal plane, and in having a sinuous suture, as well as in having trophozoites which resemble those of C. hama. It does not very closely resemble any of the other species in these

two groups, and is considerably smaller than most of the species found by Fujita (1923) in Japanese flat-fishes. It is concluded that this species is previously undescribed, and the name C. torquata n sp. is proposed for it.

Ceratomyxa renalis n. sp. (Text-Fig. 8, Figs. 118–120)

Habitat. This species occurs in the urinary bladder of Caulopsetta scapha (Forster). It extends upwards into the ureters, but it was not recovered from the kidney, and presumably does not reach the renal tubules. There was no evidence of abnormality in the host organ. The infected fish was taken by a trawler working out of Wellington in December, and was heavily infected with Sphaerospora undulans, to be described in a subsequent section of this report. It is apparently not a common species, as it was seen in but a single host.

Trophic Stages These have not been seen.

Spore Dimensions Breadth, 22.5–33.4μ (27.7μ); height, 7.3–8.5μ (8.0μ); thickness, 7.7–9.3μ (8.9μ); valvular axes, 14.7–20.1μ (17.4μ); and 8.1–19.4μ (16.0μ), capsules, 2.7–3.2μ (3.1μ) Convex angle, 67–95° (84°); concave angle, 105–143° (128°); horizontal tangential angle, 90–134° (118°); Bending index, 148°, taper index, 10°, valvular index, 44°. Breadth thickness ratios for quartiles of breadth range, 2.75, 3.20, 3.50 and 3.92.

Spore Morphology. The crescentic spore is bent rather than curved, and is made up of subequal valves which taper moderately to moderately narrow valvular tips. The spore is ordinarily seen in capsular view, when the convex margin curves smoothly, without interruption at the suture. The concave margin is smoothly curved in some spores, but is frequently somewhat flattened along each valve, and forms an obtuse angle at the suture. The two valves are often unequal in axial length (Fig. 120), and sometimes are different in shape as well, one being broader than the other. The longer valve is usually the more slender in these spores. The valves meet in a distinct, slightly elevated, straight suture. The spores seen in sutural view appear to be somewhat flattened, but this orientation is not long sustained by spores. It appears that the posterior margin is somewhat concave in sutural view, but as the spores were moving it may be that they were somewhat oblique when this impression was gained. The suture is straight when seen in sutural view.

The capsules are set near the suture, and open near the centre of the anterior face of the spore. They are nearly spherical, but slightly elongated in sutural view, the length being about 0.2μ in excess of the diameter. They converge slightly on the suture of some spores. Capsulogenous nuclei are persistent, but capsulogenous cells are, at the most, very small. The filament is not entirely obscured by the capsule wall, but the number of coils could not be determined.

The fairly large sporoplasm does not fill the spore cavity. It is finely granular, with a few dark inclusions about 0.5μ in diameter. A few refractive spherules, either in or around the sporoplasm, are usually present. The two vesicular nuclei are usually placed close together.

Spore Variability. As the infection was not a heavy one, the variability is not as fully known as for some species. It apparently centres upon differences in curvature, and differences in valvular contour, associated with inequalities in valvular length. The least curved spores are still strongly arcuate, Fig. 119 representing about the extreme of straightness observed. Some spores are somewhat more sharply curved than the one shown in Fig. 118. The extreme of valvular disparity is about that seen in Fig. 120.

Discussion. Although occurring in the urinary bladder, this species is rather like C. laxa and C. hama found in the gall bladder of the same host. The spores of C. laxa are somewhat thicker, have a little less valvular taper, and are more flattened horizontally. Differences in linear dimensions are just about at the upper limit of differences seen in samples of the other species from different hosts, or somewhat below it. The spores differ from C. laxa by having a greater breadth and a lesser thickness. The breadth: thickness ratios in C. renalis differ from those of C. laxa to a somewhat greater extent than is normally seen in samples of the same species, with a maximal value of 3.54 in the upper quartile of C. laxa and 3.92 in the same quartile for C. renalis. Differences in angular measurements are similar, in that the sample of C. renalis does not differ more than any single sample might from a species with mean values like those seen in C. laxa. The maximal difference in means is in the concave angle, which is 147° in C. laxa and 128° in C. renalis. The relationship of the angular means, however, is a little different in the two species, so that

the difference of 7° in taper index, and 15° in valvular index are essentially significant, confirming the greater length and taper of the valvular axes in C. renalis. The difference in habitat is also, in all probability, significant. The highly specialized environment of the gall bladder is not likely to be occupied by the same species as inhabit the urinary system. Differences in measurements between C. hama and C. renalis are probably significant, even on a merely numerical basis. The difference in breadth of the samples (over 4μ) is somewhat more than the difference usually seen in samples of a species from different hosts, representing about 17% of the mean breadth of C. hama, and the difference in taper ratios (28° and 10°) also appears to be significant.

Of the remaining Ceratomyxa in groups II-B-1 and II-C-1, in which this species falls, those in the general size range of this species do not inhabit the urinary system. This species is rather unusual as a urinary parasite, as most Ceratomyxa with a urinary habitat have shorter, more oval spores. It is concluded that this is a hitherto undescribed species, and is accordingly given the name C. renalis n. sp.

Ceratomyxa moenei n. sp. (Text-Fig. 9, Figs. 121–125)

Habitat. This species occurs in the gall bladder of Polyprionum moene Phillips. It has been seen in but a single fish, taken by a trawler working out of Wellington in August. The infection was extremely heavy, masses of spores having formed to plug the bile duct. The gall bladder was somewhat swollen, and appeared red and irritated.

Trophic Stages. No trophozoites were present.

Spore Dimensions. Breadth, 25.3–35.5μ (30.2μ); height, 4.5–7.1μ (5.7μ); thickness, 5.1–6.8μ (5.9μ); valvular axes, 14 1–18 6μ (16.1μ); and 11.3–17.8μ (14.7μ); capsules. 2.3–3.4μ (2.7μ). Anterior angle, 128–147° (135°), posterior angle, 166–184° (176°), tangential angle, 156–179° (167°). Curvature index, 49°, taper index, 9°, valvular index, 41° Breadth height ratio for quartiles of breadth range 4.51, 5.60, 5.60 and 5.83.

Spore Morphology. The slender spore is slightly curved, and terminates in rounded valvular tips. In sutural view the anterior margin is gently convex, often with a slight depression at the suture. In about 10% of the spores the lateral half of the valves are slightly flattened, and the anterior margin is somewhat depressed in this region. The posterior margin is nearly flat along each valve, and forms a very obtuse angle at the suture. The valves taper moderately to tips which are not very narrowly rounded for such a slender spore. In sutural view (Fig. 122), the spores are straight.

The polar capsules are large in relation to spore height. The filament is arranged in four or five coils. They are not strongly convergent on the suture, and the capsules are often surrounded by remnants of the capsulogenous cells (Fig. 125). Capsulogenous nuclei are persistent.

The sporoplasm is usually placed near the centre of the spores. It is quite transparent, and contains two vesicular nuclei. A few granular inclusions are sometimes visible. These are more prominent after staining with methyl green, and are missing in haematoxylin preparations.

Spore Variability. Variability in this species is manifested primarily in differences in valvular taper, and the amount of flattening in the lateral portions of the valve. Spore curvature is relatively constant, and the ranges of the angular measurements are quite small. Sixty per cent of the spore sample had anterior, posterior and tangential angles in the ranges 131–139°, 173–182°, and 161–173°, respectively.

Discussion. No Ceratomyxa have been previously reported from members of the Epinephelidae. The only Ceratomyxa recorded from very closely related fish is C. arcuata, which is quite unlike this species.

The spore form places this species in group II-C-1. The only species of about the same size in this group is C. urophycis (Fantham, Porter and Richardson, 1940), which has one spore valve more curved than the other, a slightly curved sutural line, and small polar capsules. It appears, therefore, that this is a new form and it has been designated C. moenei n. sp.

Ceratomyxa uncinata n. sp. (Text-Fig. 9, Figs. 126–7).

Habitat. This species occurs in the gall bladder of Pelotretis flavilatus Waite, and Caulopsetta scapha (Bloch and Schn.). It is apparently common in the former host, having been seen in the only two examined from the Wellington area. It is not common in Caulopsetta, but was found in a single host taken in the Napier area. Infected fishes have been seen in winter and summer.

Trophic Stages. These have not been identified.

Spore Dimensions. Based on samples from two Pelotretis Breadth, 27.8–36.0μ (32.2μ); thickness, 10.9–14.1μ (11.7μ); valvular axes, 18.5–25.1μ (22.1μ); and 16.7–21.8μ (19.7μ); capsules, 3.3–4.4μ (4.0μ); and 3.3–4.0μ (3.6μ). Convex angle 58–83° (72°), concave angle, 100–135° (120°); tangential angle, 86–124° (108°). Bending index, 168°, taper index, 12°, valvular index, 48° Breadth thickness ratios for quartiles of breadth range, 2.35, 2.36, 2.75 and 3.00.

A small sample from Caulopsetta. Breadth, 26.5–35.2μ (30.8μ); thickness, 11.5–14.6μ (12.6μ); valvular axes, 17.2–27.7μ (24.5μ); and 17.2–22.5μ (20.4μ); capsules 2.9–3.9μ (3.6μ); Convex angle, 50–70° (59°), concave angle, 84–125° (98°), tangential angle, 75–116° (88°) Bending index, 203°, taper index, 10°; valvular index, 39° Breadth thickness ratios for quartiles of breadth range, 2.13, 2.33, 2.62 and 2.36.

Spore Morphology. The spore is sharply bent, shaped like an inverted U, and orients itself so that it is seen in capsular view. None have been seen in sutural view. The convex margin is smoothly curved, unbroken at the suture. In some spores it is slightly inflected near the valvular tips, where the valves are slightly flattened. The opposite margin is concave, or flattened along each valve, which meet at an angle at the suture (Fig. 126–7) As the two margins are not parallel, the valves taper to moderately narrow tips. Although the valves are sometimes somewhat unequal in length, they are similar in shape. They meet in a rather broad, prominent, straight suture.

The capsules, seen from above, are nearly spherical, and lie near the suture. The capsular foramina are opposite, and there seems to be little convergence of the capsular axes on the suture. The filament is easily seen, but as it is seen in end view the number of coils cannot be counted. One filament is a right-handed spiral, while the other is a left-handed spiral. Capsulogenous nuclei are sometimes persistent, but the capsulogenous cells disappear entirely in mature spores.

The rather large sporoplasm is either symmetrical in position or asymmetrical. In the material from Pelotretix, the sporoplasm tended to be smaller, more rounded, and more asymmetrical in position. The protoplasm is finely granular, and quite transparent. It contains a few small, refractive bodies, about 0.5μ in diameter.

Spore Variability. The spore shape is relatively constant, although the outlines are affected by somewhat differing valvular lengths, and somewhat different spore curvatures. On the whole, the effect given by a spore population in a host is one of relative uniformity.

Spore populations seen in different hosts of the same species are relatively constant insofar as observations go. In the two Pelotretis, the means of the linear dimensions differed by 2.8μ in breadth, 1.1μ in thickness, 1.9 and 0.7μ in valvular axes, and 0.1μ in capsular diameter. The convex angles differed by 8°, the concave angles by 2° and the tangential angles by 3°. Because of differences in valvular length, the breadth height ratios were somewhat more variable in this than in most species, the maximal ratio for the upper quartile differing by 0.41.

The spores seen in Caulopsetta differed from the mean between the Pelotretes hosts by 1.4μ in breadth, 0.9μ in thickness, 2.4 and 0.7μ in valvular axes, and 0.4μ in capsular diameter. The spores from Caulopsetta were somewhat more bent than those in Pelotretis, the convex, concave and tangential angles differing by 13°, 22° and 20°. This difference is about the same as the maximal angular differences seen in samples from hosts of the same species in the case of C. hokarari, and C. polymorpha. In the Pelotretis material, the polar capsules were often somewhat unequal. This was rarely seen in material from Caulopsetta. It seemed unlikely that these two strains were not conspecific, despite the small differences seen in the samples.

Discussion. Of the various species of Ceratomyxa obtained from New Zealand flat-fishes, this species is most like C. laxa, but there was little evidence of transitions among spore populations of the two species suggesting that the two could be placed together. The spores of C. uncinata have a mean which is somewhat above the upper limit of the size range of spores of C. laxa, and there is a consistent difference in spore thickness. Until there is some definite evidence of transitional material between them, they must be considered as distinct strains, from the morphological sense, and presumably in the biological sense.

Of the other species of Ceratomyxa in group II-B-1, the most similar is C. toitae (Fujita, 1923), which also occurs in flat-fish hosts. Although it is bent like C. uncinata, however, the valves are unequally curved, and the capsules very small (2μ) and strongly convergent. It seems, therefore, that this form is previously underscribed, and it is designated as C. uncinata n. sp.

Ceratomyxa polymorpha n. sp. (Text-Fig. 10, Figs. 128–137)

Habitat. This species is a common parasite of the gall bladder of Physiculus bachus (Bloch and Schn.). It occurs in about 80% of the red cod taken by trawlers working out of Wellington, throughout the year. Even where the infection is heavy, there are no obvious signs of abnormality in the host organ, although the bile becomes yellow and cloudy.

Trophic Stages. The trophozoites include very small, hyaline forms, about 5μ in diameter or a little less, apparently arising as a result of budding. The larger trophozoites reach a maximal size of 40μ, and are rounded or amoeboid in shape. They have narrow, elongated, blunt lobopodia. None have ever been seen in rapid movement. They often mass together as they are attached to the walls of the gall bladder, but do not fuse together.

The ectoplasm is sometimes quite distinct, especially in the pseudopodia. It is clear, colourless, and highly transparent. The endoplasm contains a number of granules, rather small and appearing dark in dark contrast phase. These are mixed with another type of granule of about the same size which is bright in dark contrast phase. Both granules are somewhat less than 0.4μ in diameter. In dark field illumination, the whole endoplasm appears as bright, granular material. A number of small spherules, less than 1.0μ in diameter are also seen. These appear dark in dark contrast phase. They are not stained with Janus green B.

Spore formation may be monosporous or disporous, with the latter more common. The sporoblasts begin as nearly spherical bodies, and as they enlarge, the capsulogenous cells become quite vacuolated, with meshy protoplasm (Fig. 129). In the young sporoblasts the suture is usually somewhat sinuous, straightening as the sporoblast reaches the diameter of the mature spore. In most cases the capsulogenous cells disappear early (Fig. 130), but occasionally, mature spores will still contain remnants of the capsulogenous cells (Fig. 131). The valvular nucler are stationed at the valvular extremities. They, like the capsulogenous cells, may disappear rather early, or may still be visible in otherwise mature spores (Fig. 132).

Spore Dimensions. Based on samples from three hosts Breadth, 23.0–44.5μ (33.7μ); height, 11.1–16.4μ (14.6μ); thickness, 11.1–18.0μ (14.3μ); valvular axes, 12.0–25.5μ (18.9μ); and 9.0–20.5μ (15.4μ); capsules, 4.4–5.5μ (4.9μ); by 4.0–4.5μ (4.1μ); and 1.6–4.0μ (3.3μ); by 1.6–4.0μ (2.9μ) Anterior angle, 90–142° (114°); posterior angle, 163–244° (203°), tangential angle, 117–180° (158°) Curvature index, 43°, taper index, 45°, valvular index, 89° Convex angle, 93–124° (105°), concave angle, 150–231° (192°), tangential angle, 104–180° (156°). Bending index, 63°; taper index, 36°; valvular index, 87°. Breadth height ratios for quartiles of breadth range, 2.19, 2.25, 2.43 and 2.49.

Spore Morphology. The bulky, somewhat curved spore has broad valves terminating in broadly rounded tips. Seen in sutural view the anterior margin varies from nearly straight to sharply convex. The posterior margin very nearly parallels the anterior margin in most spores, although in some the posterior margin is convex and the anterior margin nearly straight (Fig. 133). Some spores are bent rather than curved .In these the posterior margin is generally straight (Fig. 134). In many spores, the anterior and posterior margins are interrupted by a constriction at the suture. The valves are often unequal in axial length, and ill-matched in shape, giving one the impression of valves assembled separately and put together at random. They meet along a distinct, somewhat elevated, rather broad suture which is usually nearly straight, but is sometimes somewhat oblique.

The oval to sligtly pyriform capsules are often quite unequal in size. The filament is distinctly visible, and is arranged in from four to seven tight coils. In some of the smallest capsules no filament can be seen. They are difficult to extrude in unkinked condition. It appears that the maximal length is about 45μ to 50μ, although many seem distinctly shorter. The filament from the smaller capsule is shorter, and it seems that the length of the filament is roughly proportional to the capsular size. The capsulogenous nucler differ considerably in their tendency to persist.

The rather large, binucleate sporoplasm is variable in position. When it is asymmetrically arranged, the bulk of the sporoplasm is found in the larger valve. It contains a number of small, irregular inclusions, about 0.3–0.5μ in diameter, and larger ones averaging about 1.5μ in diameter. The larger inclusions often tend to adhere to the spore membrane, and occur in the spore cavity as well as the sporoplasm.

Spore Variability. This species is quite variable, the valves being inconsistent in shape, curvature or bending, and often quite different in shape as well as size. Tri-valved and tetravalved spores are sometimes common. During the winter months populations of spores with about 60–75% of the spores in triad from occur. During the summer months, however, relatively few occur, and in one host taken in January, not a single triad spore was seen. Tertrad spores are never as common as triad spores, but sometimes make up to about 5% of the spores population. The tetrad spores are usually ill-formed, and where the valves are quite unequal in size, are almost amorphous. No spores with a differing number of valves and capsules were seen.

Although the species is common, it was found in several hosts in which there were few mature spores, and eventually, full samples for measurement were taken from but three of the infected hosts, one taken in winter, one in spring, and one in summer.

The sample means for breadth varied from 29.8μ to 38.3μ The mean of all samples was 33.7μ, so that the maximum deviation of a sample mean from the mean of all samples was 4.6μ, representing 13.6% of the mean breadth. On a similar basis, the maximal deviation of a sample mean from the mean of all samples for spore height was 6.9% of the mean height, and the maximal deviation of spore thickness 5.6% of the mean thickness. Sample means had maximal deviation from the mean of all samples of 14.3% of the longer valvular axis, and 8.6% of the shorter valvular axis. It is evident that a significant difference in dimensions of part of the spore did occur in these different hosts. Using small sample methods, it was easy to demonstrate differences in the samples with a p. value of 0.01 or less.

In the case of angular measurements, the anterior angle was more stable than either of the others. The sample means agreed with a total difference of but 3° from smallest to largest for the anterior angle. The maximal deviation of a sample mean from the mean of all samples was 15° for the posterior angle, and 10° for the tangential angle.

There is considerable compensation in the relationship of the various angular dimensions. If the total range of the posterior angle is divided into quartiles, the mean anterior and tangential angles show a continual change between the quartiles. The results are summarized in Table II.

There was no evidence in the three samples, nor in the smaller samples from other hosts, to support the idea of a changing size of the spore with season. The only thing that can be said with some certainty is that the frequency of spores with triad and tetrad form was highest in the samples taken during the winter months.

Discussion. Although the family Gadidae, to which Physiculus bacus belongs, is one of the most receptive to Myxosporidia, there are not a large number of reports of Ceratomyxa from among its numbers. C. arcuata has been reported from Gadus merlangus (Dunkerly, 1921), and C. acadiensis and C. urophycis from Urophycis chuss. (Ellis, 1930; Fantham, Porter and Richardson, 1940). Dunkerly (1921) also reports an unidentified Ceratomyxa from Molva molva. None of these species bears a close resemblance to C. polymorpha.

This species falls into group I-A-1 or II-A-1, depending on the spore curvature. Of the species in group I-A-1, none approach the size of C. polymorpha. Of those in group II-A-1, none with a breadth comparable to that of C. polymorpha have a spore height which is nearly as great. It is evident, therefore, that it is a hitherto undescribed form, and the name C. polymorpha n. sp. is proposed for it.

Ceratomyxa hokarari n. sp. (Text-Fig. 10, Figs. 139–145)

Habitat. This species occurs in the gall bladder of Genypterus blacodes (Bloch and Schn.). It is a common form, having been found in 7 of 10 fishes examined during various seasons of the year. Although some of the infections were quite heavy,

there was no evidence of damage to the host organ. All of the infected fishes were taken by trawlers working out of Wellington.

Trophic Stages. The trophozoites are apparently rather delicate, for they are usually missing entirely, and have never been seen in a motile condition. They are irregular in shape, with long, slender, narrowly rounded pseudopodia, usually located near the ends of a somewhat elongated body. The transparent endoplasm contains a variable number of refractive spherules, about 1. 0μ in diameter. The ectoplasm is not easily distinguished, but the spherules do not extend into the pseudopodia. Although an occasional monosporous trophozoite is seen, the majority are disporous, with the maturing spores carried in tandem.

Spore Dimensions. Based on samples from six hosts Breadth, 24.2–48 4μ (35.6μ); thickness, 11.0–13.2μ (11.9μ); valvular axes, 16.5–35.2μ (27.1μ); and 15.4–33.0μ (23.8μ), capsules, 2.2–4.4μ (3.9μ); Convex angle, 32–106° (70°); concave angle, 35–155° (106°); horizontal tangential angle, 25–144° (94°); Bending index, 184°, taper index, 12°, valvular index, 36°, thickness ratios for quartiles of breadth range, 2.33, 2.69 2.98 and 3.69.

Spore Morphology. The sharply bent spores have sub-equal valves, tapering gently to rather narrowly rounded tips. They usually orient themselves so that they are seen in capsular view, and relatively few are seen in sutural view. In sutural view the spore has a relatively straight anterior and posterior margin (Fig. 140), not quite parallel, and the suture is straight In capsular view the spore is crescentic, with rather long, slender, gracefully curved valves. The two valves are usually almost equal in size, but occasional spores are seen with considerable disparity in valvular length (Fig. 144). They meet in a slightly elevated, distinct suture, which in some stained spores appears as a double line. The suture is almost circular.

The capsules are oval in sutural view, the length slightly exceeding the breadth. They terminate in short, slender necks. About four or five coils can be seen. In capsular view the filament is distinctly visible in the circular capsules. It does not appear to converage much on the suture. The capsulongenous nucler may or may not be persistent. No other remnants of the capsulogenous cells are seen in mature spores. The capsules may be centred on the anterior face of the spore, or be placed toward the convex or concave border.

The sporoplasm is finely granular, with a few small, refractive inclusions. The two nucler are relatively small, and are usually placed close together. In some spores they show a structure almost identical to that shown for C. blennius by Noble (1942)

Spore Variability. The species shows a considerable range of spore shapes, the principal variation being in relative length of the valvular axes, and in the amount of curvature. The approximate range of variation is shown in Figs. 142–145. The spores in any one host show a somewhat smaller range than is indicated by the diagrams.

A total of six samples were compared, to obtain a picture of the amount of variation that might be found in samples from different host animals. The maximal difference of a sample mean from the mean of all samples was 15% of the mean in the case of breadth. The valvular axes exhibited differences in the same order of magnitude, the maximal deviation of a sample being 12.5% for longer valve, and 12.6% for the shorter valve. The maximal divergence of the spore thickness from the mean of all samples was 7% of the species mean.

Like the linear dimensions, the angular measurements were subject to considerable variation. The greatest deviation of a sample mean from the species mean was 16° for the convex angle, 23° for the concave angle, and 22° for the tangential angle.

The differences between the means of the various samples were often highly significant from the statistical point of view. In a number of instances the differences proved to be significant well beyond the. 001 level. It is evident that in the complex of factors correlated with life in different host animals at different seasons, conditions which result in real differences in size and contour of the spore are encountered. These are often sufficient to produce statistically significant differences in linear or angular dimensions. The statistical methods are, evidently, too delicate an instrument to be used for species recognition. This might be anticipated, as statistical methods have their routine use in the genetic studies of populations within the species group.

Although the individual angles measured vary considerably in different samples, the relationships between the angles are relatively stable. The bending index is quite variable having been as high as 217° in one sample, and as low as 143° in another sample. However, the valves which are more or less curved retain a similar shape, and the valvular index varied only from 34° to 43°, while the taper index varied only from 9° to 17°. It would appear, therefore, that in comparing spore populations, considerable weight should be given to the relationship of the angles, perhaps more than to the angles themselves.

A much more extensive series of infected hosts would require examination before firm conclusions could be drawn concerning the effects of season upon spore shape and size. There was no evidence of a relationship of the season to spore curvature, or other angular measurements. There was, however, a definite relationship between spore breadth and season, insofar

as the samples studied are concerned. All of the samples taken during the winter season had means below the mean of all samples, while all of the samples taken during the warmer months had means well above the mean of all samples. While this may have been forturtous, the chances of this occurring in all of six hosts is not high. The evidence would certainly suggest that it would be worth while looking for a correlation between spore breadth and such seasonal factors as water temperature, nourishment of the host, etc.

Discussion. It is interesting to note that the only other Ceratomyxa to have been reported from a member of the Ophidiidae is C. arcuata, with spores sharply curved rather than bent, with smaller capsules and a more slender shape. C. inversa, also found in Genypterus, has straight spores which are considerably larger.

C. hokarari falls into group II-C-1. Of the species in this group, only C. urophycis is very similar. This species, however, has one valve somewhat more curved, a slightly curved sutural line, and small, pyriform polar capsules. As the form cannot be considered identical with any of the previously described species, the name C. hokarari is proposed for it.

Ceratomyxa angusta n. sp. (Text-Fig. 11, Figs. 145–147)

Habitat. This species occurs in the gall bladder of Hypoplectrodes semicinctus (Cuv. & Val.) and Helicolenus percoides (Richardson). It is apparently not a very common form, having occurred in but a single example of each host Both infected hosts were taken by trawlers working out of Wellington. In neither host was there evidence of damage to the host organ.

Trophic Stages. Trophozoites have not been seen.

Spore Dimensions. From Hypoplectrodes, based on spores measured in water suspension, following fixation in sublimate acetic and storage in alcohol Breadth, 37.0–47.4μ (42.1μ); height, 5.1–6.2μ (5.5μ); valvular axes, 19.7–26.5μ (23.5μ); and 13.5–22.5μ (18.2μ); capsules, 2.3–3.4μ (2.7μ). Anterior angle, 143–160° (153°), posterior angle, 176–193° (183°), tangential angle, 169–180° (179°) Curvature index, 24°, taper index, 4°, valvular index, 30° Breadth height ratios for quartiles of breadth range, 7.5, 7.5, 7.8 and 7.6.

From Helicolenus. Breadth, 34.2–57.8μ (48.1μ); height, 5.4–6.5μ (5.7μ); thickness, 5.4–5.9μ (5.7μ); valvular axes, 21.6–30.2μ (25.5μ); and 17.3–28.0μ (23.0μ), capsules, 3.2–3.8μ (3.3μ); by 2.7–3.2μ (3.1μ). Anterior angle, 143–160° (153°), posterior angle, 177–186° (181°), tangential angle, 172–179° (175°) Curvature index, 26°, taper index, 6°, valvular index, 28° Breadth height ratios for quartiles of breadth range, 7.0, 8.5, 8.5 and 8.65. Only a small sample were measured for spore thickness.

Spore Morphology. The slender, straight spore terminates in narrow, rounded valvular tips In sutural view the anterior margin of each valve is nearly straight, sloping upwards to meet in an obtuse angle at the suture. The posterior margin is nearly straight, but is slightly curved in some spores (Fig. 147). The valves are elongated, and may be equal or quite unequal. They are approximately the same in general shape, even when unequal. They meet in a rather narrow, slightly elevated suture, which is often set in a slight depression. Although the gradient of the valvular taper is slight, the valvular tips are narrowly rounded. The thin spore membrane is deformed easily by pressure and the forces acting during dehydration. It is not uncommon to see a spore with the valves collapsed shut over the whole length, except for the central region containing the sporoplasm In capsular view (Fig. 146) the spore is straight and the amount of valvular taper about the same as that seen in sutural view.

The polar capsules are nearly spherical to broadly oval, with very short, narrow necks. They converge somewhat on the suture, and open on the anterior margin In capsular view they are opposite, or nearly so. The filament is rather indistinct in fresh spores, and appears to be very delicate. It forms from five to seven coils Capsulogenous nuclei are persistent in the majority of spores, and in many there are some remnan's of the capsulogenous cells.

The sporoplasm is restricted to the central region of the spore, lying beneath the capsules and extending upwards around and between them Occasionally there are rounded masses of sporoplasm which have become separated from the main mass (Fig. 146) and lie in the more lateral portions of the valves. The sporoplasm is finely granular, with few inclusions. It contains two vesicular nuclei.

Spore Variability The most variable feature of the spore is the axial length of the valves, which may be equal or unequal, and vary considerably in actual length. The difference in the spore size of the forms found in Hypoplectrodes and Helicolenus may be attributed, in large part, to the fact that the former were fixed when measured. The approximately 20% loss in spore breadth is not far out of line with the normal shrinkage to be expected during

fixation with sublimate acetic. It seems probable that the spores shrink somewhat more in breadth than in sutural diameter during fixation.

It is evident that the angular measurements are less affected by fixation than the linear measurements. The close agreement of the angular measurements in the two samples is, no doubt, related to the rather constant spore shape, and to the fact that the ranges observed in the angular measurements were relatively short. It appears that there is somewhat more variability in the angular measurements of the fixed material, but the mean values remain essentially unchanged.

Discussion. The hosts belong to the families Serranidae and Scorpaenidae. Except for species reported in this paper, no Ceratomyxa have been previously reported from the Serranidae. Fujita (1923) reported C. yoichiensis and Jameson (1929) C. starksi from Scorpaenids. The spores formed in both of these species are much smaller than those produced in C. angusta

The spore form is such that the species belongs in group I-C-1. The only species in this group which resembles this form is Fujita's (1923) C. japonica, which has a spore with a much greater height (11–13μ). Other elongated species have spores which are more curved, more sharply tapered, or are quite different in dimensions As this appears to be previously undescribed, it has been designated C. angusta n. sp.

Ceratomyxa aggregata Davis (Text-Fig. 11, Fig. 148)

Habitat. This species occurs in the gall bladder of Dactylopagrus macropterus (Bloch and Schn.). It is not common, having been seen as a light infection, mixed with C. insolita, in a single host. The infected fish was taken in August, by a trawler working out of Wellington. There was no evidence of damage to the host organ.

Trophic Stages The trophozoites have not been seen.

Spore Dimensions Based on a small sample of 6 spores Breadth, 41 4–60 6μ (51 5μ), height, 5 9–7 8μ (7 1μ), valvular axes, 22 0–32 2μ (26 8μ) and 21 6–29 4μ (25 5μ), capsules 2 4μ by 2 0μ Angular measurements were not taken. as the slender valves may be bent or twisted in any direction.

Spore Morphology The central region of the spore is enlarged, and the lateral portions of the valves narrow, often flattened, and often bent or twisted In sutural view the central region of the spore has a convex anterior and posterior margin, the curvature being broken, in most cases, as the more lateral portions of the valves are reached. These empty parts of the valves may be straight, curved forward or back, or bent to one side. They are often bent in different directions, and are sometimes collapsed Despite differences in contour of the empty portions of the valves, they are approximately equal in axial length. There is no evidence of a septum at the base of the empty portions of the valves. The valves meet in a fairly prominent, straight suture.

The capsules are set near the anterior margin, and near the suture, on which they converge Most of the spores appear a little immature, with prominent capsulogenous cells. It seems probable that the capsules might increase in size somewhat, as they mature Valvular nuclei, however, cannot be seen.

The rather large sporoplasm fills the central region of the spore. It contains a few refractive granules, and two vesicular nuclei.

Discussion. The original description of C. aggregata (Davis, 1917) is based on material from Leiostomus xanthurus and Micropogon undulatus, members of the Sciaenidae One of the more characteristic traits of C. aggregata is the aggregative tendencies of the trophozoites, and a final identification of this form must await the comparison of the trophic stages from Dactylopagrus with those seen by Davis.

There are some differences in the spores described by Davis and those seen in the New Zealand material. The most outstanding difference, perhaps, in the larger size of the capsules in Davis's material, which may be explained on the basis of immaturity of the spores seen in Dactylopagrus There also appears to be somewhat more sharp separation of the more lateral parts of the spore valves in the New Zealand material However, until more material can be examined, the differences appear to be insufficient to permit separation of the two forms. They have spores of about the same size, and general shape, and in both strains the spores tend to collapse laterally. It seems preferable, at the present, to consider the two forms conspecific.

Ceratomyxa nitida n sp. (Text-Fig. 11, Fig. 149)

Habitat This species was seen in a single Peltorhamphus novae-zeelandiae Gunther. The host fish was taken by a trawler working out of Napier in September. There was no evidence of damage to the host organ. The infection was mixed with Leptotheca pinguis

Trophic Stages These are unknown.

Spore Dimensions Based on a sample of 13 spores Breadth, 52.9–63.6μ (58.3μ); height, 10.8–13.7μ (12 1μ); valvular axes, 31.7–34.8μ (32.9μ) and 26.0–31.8μ (28.6μ); capsules, 5.4–6.4μ (5.9μ) by 3.9–4.9μ (4 4μ). Anterior angle, 115–131° (124°); posterior angle, 155–173° (165°); tangential angle, 144–162° (155°). Curvature index, 71°; taper index, 10°; valvular index, 41°. Mean breadth: height ratio, 4.81.

Spore Morphology The spore is straight, or nearly straight, in capsular view, the capsules slightly rotated in position In sutural view the two bulky, moderately tapered valves curve slightly, and meet in a heavy, broad, elevated suture. The two valves are often somewhat unequal in length, but have essentially the same shape Despite the length of the valvular axes, the valvular tips are broadly rounded.

The large, pyriform polar capsules have narrowed necks, which are relatively long and tapered. They converge sharply on the suture, and are somewhat rotated. The filament appears to form a double coil in the capsule. The coils are set in a diagonal direction when the spore is seen in sutural view. The filament is quite delicate, but from five to seven coils can be seen Capsulogenous nuclei are persistent, and in many spores vacuolated remnants of the capsulogenous cells can also be seen.

The large sporoplasm is essentially central in position, but often extends farther along one valve than the other In a few spores it extends nearly to one valvular tip. It is rather coarsely granular, and contains a number of small, refractive granules, and a few refractive spherules 1μ in diameter. The sporoplasm contains two rather large, vesicular nuclei Small amounts of finely granular and rather transparent material and an occasional refractive spherules occur in the spore cavity outside of the sporoplasm.

Discussion Although the infection was relatively light, and only 13 spores were properly oriented for measurement, the spores seen were relatively stable in form, and it seemed possible to give a reasonable characterization of their form. The species falls in group II-B-1 Of the species in this group, it most resembles C. protopsettae (Fujita, 1923) and C. drepanopsettae Awerinzew (1908) in spore breadth. Both of these species occur in flat-fishes. In both of these species, however, the two valves are dissimilar in shape, with one valve more slender and more elongated. It is, on the whole, more similar to C. protopsettae than to C. drepanopsettae, but as Fujita states that the suture is indistinct in that species, it seems evident that the two cannot be the same As this species cannot be equated with previously described forms, it is given the name C. nitida n sp.

Ceratomyxa inversa n sp (Text-Fig. 11, Fig. 150)

Habitat This species occurs in the gall bladder of Genypterus blacodes (Bloch and Schn.) It has been found in but a single host, taken by a trawler working out of Wellington in March. The bile was so heavily infected that it was a milky yellow colour, and seemed less viscous than usual. There was no evidence of any abnormality in the host organ, however.

Trophic Stages Trophozoites are extremely varied in size and shape Small forms about 8μ in diameter are common, as are large, sporulating forms of about 150μ in length. The motile organisms move very slowly. They are basically pyriform in shape, with the anterior end rounded and tapering to the region of maximal breadth about one-third of the way back from the front end. The remainder of the body narrows, forming a large and bulky posterior process In small forms, the posterior process is relatively short and narrow, and terminates in a sharp point, while in larger forms the process is wider, longer, and more clavate in shape Sporoblasts are carried in the anterior, expanded part of the body Small slender, tapering, pointed pseudopodia occur at the anterior end of the motile forms Floating trophozoites and those attached to the wall of the gall bladder assume a clavate form, with an enlarged region containing the sporoblasts located somewhere along the body. It is not uncommon to see the attached forms with the enlarged region in contact with the wall of the gall bladder, looking rather like the motile forms, but not indulging in movement Floating

or attached forms develop pseudopodia at various points on the body surface. These pseudopodia are larger than those seen in the motile forms, and often branch.

The trophozoites contain few inclusions, and these are never prominent. The endoplasm is finely granular, containing a number of very small spheres, which are either black or light in dark contrast phase, but never bright-rimmed. They are scarcely visible in bright field illumination Small, spherical inclusions, averaging 1μ in diameter, appear as dark spheres in dark contrast phase, and are not seen in dark field. They persist in fixed and stained slides where they are acidophilic.

Despite the large size of the trophozoites, none were seen with more than two sporoblasts. The young spores become prominent early in development As they increase in size, they become more elongate, and tend to lie side by side, without crossing Unlike some of the species with long, slender valves, this one does not tend to have the lateral extremities of the spore valves curled about the central region of the spore during development.

Spore Dimensions Breadth, 51.1–73.7μ (61 5μ); height, 6.9–9.3μ (8.5μ); thickness, 7.7–10.0μ (9.0μ); valvular axes, 25.5–38.7μ (33.5μ) and 20.0–37.2μ (30.1μ); capsules, 3.1–4.6μ (3.4μ) by 2.3–3.4μ (3.1μ). Anterior angle, 111–188° (152°), posterior angle, 141–215° (180°), tangential angle, 137–180° (167°) Curvature index, 28°; taper index, 13°; valvular index, 28°; Convex angle, 112–153° (132°); concave angle, 134–173° (164°); tangential angle, 130–180° (158°). Bending index, 64°; taper index, 6°; valvular index, 32° Breadth height ratios for quartiles of breadth range, 6 33, 6 40, 7 90 and 9.05.

Spore Morphology The slender spores are somewhat curved and bent, and normally orient themselves to float upside down, with the capsular surface down As a result, relatively few spores are seen in either capsular or sutural views, most being seen in basal view. Seen in basal view the spores are straight to somewhat bent, with the straight spores tending to exhibit some vertical curvature Spores are rarely both bent and curved. The two valves, often somewhat unequal in axial length, are of similar shape, and have a moderate taper. They meet in a rather narrow, elevated suture, which is sometimes set in a slight depression Few spores are seen in sutural view, but when they appear in this orientation, the anterior margin tends to be more deeply marked by the sutural constriction than the posterior margin (Fig. 150) In general, as the angular measurements indicate. spores are somewhat more bent than curved.

The polar capsules are spherical in basal view and capsular view. They are opposite or nearly so, and usually lie near the axis of the spore Capsulogenous nuclei are usually persistent. The capsulogenous cells are not, however. The filament is distinctly visible, and in spores seen in sutural view, appears to make from four to six coils. The capsules converge on the suture.

The sporoplasm is moderately large, extending from ⅓ to ½ the length of one valve, and usually in contact with the bases of the capsules. It is sometimes centred in the spore, and sometimes quite asymmetrically placed. It is rather transparent, and contains a few bright, refractive spherules as well as two vesicular nuclei.

Discussion The only other Ceratomyxa reported from the Ophidiidae are C. arcuata and C. hokarari. Both species have been seen in New Zealand material, and neither can be mistaken for C. inversa, both having strongly crescentic spores. It was thought, initially, that C. inversa might represent a straight strain of C. hokarari, but the capsules are somewhat different, and the valvular dimensions are quite different.

This species falls into group II-B-1 or II-C-1, with the majority of spores falling into the latter group In the former group, only C. protopsettae and C. drepanosettae have similar spore breadth. Both of these species are parasites characteristic of flatfishes, and differ in spore form, with dissimilarly shaped valves, and somewhat different spore dimensions (Fujita, 1923; Awerinzew, 1908). The species in group II-C-1 include C. ramosa (Awerinzew, 1907) and C. microstomi in the same general size range C. ramosa has trophozoites with a few much ramified pseudopodia which anastomose as well as branch. The spore height is greater than in C. inversa. The spores of C. microstomi (Fujita, 1923) are less curved, and the sporoplasm is marked by coarse, oily spherules Since this form does not agree with any of the previously described species, it has been named C. inversa n sp.

Ceratomyxa elongata n sp. (Text-Fig. 11, Figs. 151–154).

Habitat This species occurs in the gall bladder of Lepidopus caudatus Infected hosts were taken in the winter and spring by trawlers working out of Wellington.

It is common, occuring in about half of the Lepidopus examined Although some of the infections were very heavy, there is no evidence of damage to the host organ.

Trophic Stages. The trophozoites are about 5μ in diameter at their smallest, and about 45μ in diameter when at maximal size. They often gather together in large masses, attached to the walls of the gall bladder. The individual outlines of the trophozoites remain distinct Younger trophozoites are often pyriform in shape, with two or three slender, tapering pseudopodia None of these have exhibited motility Larger trophozoites tend to be more or less clavate to amoeboid in shape.

The protoplasm is rather clear, containing a variable number of small, refractive inclusions about 1.0μ in diameter, which do not persist in permanent preparations Ectoplasm can be distinguished only in pseudopodia. The sporoblasts are easily seen in fresh trophozoites Originally quite small, they become oval bodies as differentiation continues At this time they look very much like mature spores of a Leptotheca-like species, surrounded by a clear area, somewhat resembling the membranous remnant of a sporoblast. The clear area, however, is made up of the curved and flattened lateral portions of the valves which are more or less wrapped about the central portion of the spore. The lateral portions of the valves apparently do not expand until the spore is liberated from the trophozoites Only disporous trophozoites have been seen.

Spore Dimensions Fresh material from one host Breadth, 72.6–99.0μ (91.0μ); height, 7.7–11.0μ (9 6μ); thickness, 6.6–8.7μ (7.8μ); valvular axes, 36.6–53.9μ (48.4μ) and 36.3–47.3μ (39.6μ); capsular diameter, 2.2–3.3μ (3.0μ). Anterior angle, 137–166° (152°); posterior angle, 159–188° (177°); tangential angle, 155–180° (172°). Curvature index, 31°; taper index, 5°; valvular index, 25°. Breadth: height ratios for quartiles of breadth range, 7.35, 9.40, 10.42 and 9.65.

A sample of fixed spores from another host, studied in water suspension. Breadth, 63–89μ (76.0μ); height, 6.5–8.5μ (7.3μ); thickness, 6.5–7.5μ (7.0μ); valvular axes, 32–50μ (40.2μ) and 30–40μ (34.3μ). Anterior angle, 125–180° (152°); posterior angle, 153–201° (175°); tangential angle, 146–180° (166°). Curvature index, 33°; taper index, 9°; valvular index, 23°.

Spore Morphology The slender, slightly curved spore is quite large, and has a central, somewhat inflated region In sutural view the anterior margin is nearly straight for the greater part of the length of each valve, with a convexity at the central region adjacent to he suture. The posterior margin is flattened, or slightly concave, and in some instances shows evidence of a somewhat expanded central region also. The margins of the valves are not quite parallel, each tapering very gradually to quite narrowly rounded tips In capsular view (Fig. 152) the spore is straight or nearly so, with similar taper. The two valves meet in a straight, raised suture which is moderately conspicuous.

The polar capsules are relatively small, and appear to remain permanently juvenile Capsulogenous cells were invariably present in all hosts, usually forming a dense protoplasmic covering around the capsules In some spores it is not possible to trace the line of separation between the two capsulogenous cells beneath the suture Even in these spores, however, the capsulogenous mass is bilobed. The filament tends to be indistinct, althought about four or five coils appear to be formed.

The sporoplasm is a small mass, located centrally, and extending but a short distance along the valves at the most. It is closely associated with the capsules, often appearing to be in close contact with the capsulogenous cells. It contains a few refractive bodies, and two vesicular nuclei. The nuclei are usually placed close together, but are sometimes distant.

Spore Variability The variability of the spores is primarily one centred in the length of the valvular axes. They may be somewhat longer or shorter, and the two valves may be equal or quite unequal. The spores vary in curvature from nearly straight to somewhat curved. They are never strongly arcuate, nor are they conspicuously bent.

Spores from different hosts are essentially similar in size and shape. Only small samples from most hosts were measured. These fall well within the range of size indicated by the full sample quoted in the dimensions section. The fixed spores give evidence of a marked shrinkage, particularly in breadth. They have a more variable shape, angular measurements indicating this in their greater range, but the mean angular measurements of fixed and fresh spores are almost identical.

Discussion C. obovalis (Fantham. 1930) is the only member of the genus reported from the Trichiuridae. It occurs in the same host species, Lepidopus caudatus Its Leptotheca-like spores are in no way similar to those seen in this species.

The spores fall in groups I-C-1 or II-C-1, depending on the amount of spore curvature This species falls in a space between C. mesospora (Davis, 1917) and C. tylosuri (Awerinzew, 1913) in group I-C-1, being significantly larger than the one and smaller than the other In II-C-1 it is larger and more slender than C. microstomi (Fujita, 1923), less bent than either C. osmeri (Fujita, 1923) or C. furcata (Fujita, 1923), and smaller than C. flagellifera As it cannot be identical with any of the previously described species, it has been designated as C. elongata n sp.

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