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Volume 14, 1881
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Art. XIX.—Notes on some Pulmonate Mollusca.

[Read before the Philosophical Institute of Canterbury, 2nd June, 1881.]

Plates III. and IV.

Patula coma, Gray. The jaw is slightly arcuate, with the ends attenuated; it is marked with distant striæ which converge slightly towards the upper margin. (Plate III., fig. L.)

The radula is .01 inch in breadth. Teeth 13–1–13, of which 6 may be called laterals. The central tooth is tricuspid, the side cusps short and ronnded and without cutting points, the median cusp long and narrow with a small cutting point at the extremity; the base of attachment is broad and rectangular, and extends beyond the cutting point of the median cusp. The lateral teeth are similar to the central, but the base of attachment is oblique. The seventh tooth has the cusps nearly equal, and the inner side

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cusp as well as the median has a cutting point. No. 6 is intermediate between No. 7 and the laterals. Towards the margin the cusps get smaller and the cutting points larger, but the outer side cusp never has a cutting point. (Pl. III. fig. A.) The teeth are arranged in nearly straight transverse rows. (Pl. IV., fig. g.) The specimen from which the drawings are taken came from Dunedin, but I have found the same species at Queenstown. There are 5–5½ whorls, and the ribs are less than .01 inch apart; the aperture is oblique.

Patula hypopolia, Pfeiffer. The jaw is arcuate, not attenuated at the ends, which are rounded; it is transversely finely striated. It resembles the jaw of P. igniflua, (Pl. III., fig. M.)

The radula is .02 inch in breadth, with about 133 transverse rows of teeth; the rows are nearly straight. (Pl. IV., fig. H.) The teeth are 26–1–26, of which 10 or 11 may be called laterals. The central tooth has a prominent median cusp, with two minute side cusps: the base of attachment is longer than broad, enlarging posteriorly, and extending far beyond the median cutting point. The laterals are bicuspid with a cutting point on each, the inner being the larger. No. 12 is also bicuspid, but the reflected; portion and the cutting points are very oblique. Towards the margin the cutting points increase to four. (Pl. III., fig. B.)

This specimen is also from Dunedin, where the species is not uncommon. Some specimens are entirely “horny-cinereous,” as in the typical P.hypopolia, but some are slightly spotted, and others strongly spotted and marked with rufous, thus passing into P. iota. Both forms are sub-carinated. The peculiarity of the jaw in this species and in P. igniflua, is no doubt sufficient to remove them from Patula; but in the absence of full information I make no attempt to place them properly.

Patula igniflua, Reeve. The jaw is arcuate, with rounded ends, with distant transverse striæ. It is membranaceous, soft, and pale horn-coloured. There is no median projection. (Pl. III., fig. M.) The striations of the jaw appear to arise from folds in the membrane; it gives the appearance of the jaw being made up of many pieces slightly imbricated, but I could not satisfy myself that they were really distinct.

The radula is .03 inch in breadth, with about 70 nearly straight transverse rows of teeth. (Pl. IV., fig. I.) The teeth are 37–1–37, with 11 laterals on each side. The central tooth has a single cusp, surmounted by a cutting point; the base of attachment projects beyond the cutting point. The laterals are bicuspid, but without a cutting point on the outer cusp. The inner marginals are also bicuspid, but the cutting point is longer. The outer marginals have the reflected part and the base of attachment much reduced, but the cutting points are very long and sharp. (Pl. III., fig. c.)

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This fine species is not uncommon near Dunedin. It nearly always has obscure spiral grooves. In colour it is either horn-coloured, or irregularly marked, or flammulated with red. There is a variety with membraneous, deciduous ribs, which I suppose may be the P. portia of Gray. The dentition of both is the same, and the membraneous ribs are easily removed. If I am right in identifying this ribbed variety with P. portia, then Dr. Gray's name will stand for both. There is a mucous gland at the posterior end of the foot.

Placostylus bovinus, Brugière. Jaw arcuate, attenuated at the ends; membranaceous, soft, transversely striated by infoldings of the membrane, giving the jaw the appearance of being composed of many pieces. (Pl. III., fig. o.)

Radula .17 inch in breadth, and length about two and a-half times as much, with about 140 transverse rows of teeth. These rows are nearly straight, forming a very obtuse angle salient posteriorly. (Pl. IV., fig. K.) Teeth 55–1–55, of which 28 are laterals. The central tooth has a single cusp with rounded shoulders at its base; the cutting point is short and broad; the base of attachment broadens posteriorly and does not extend as far as the apex of the cutting point; the lateral teeth are bicuspid, with the outer cusp small; there is no cutting point on the interior cusp near the central tooth, but at about the twelfth row a small cutting point appears; this gets larger to No. 20, then smaller again, disappearing in the marginals altogether. At about the fortieth row the central cutting point disappears also. (Pl. III., fig. D.)

The specimen from which the drawings were taken was given me by Professor T. Jeffery Parker, and had originally come from the north part of the Auckland district. Although there is considerable difference in the published descriptions of P. bovinus and P. novoseelandicus, I think that they are the same species, as nearly every specimen that I have examined combines characters of both. Usually they have the general form and colour described as characteristic of P. novoseelandicus, together with the seven whorls and the cherry-red mouth of P. bovinus. Although the shell has seven whorls, the animal has only three and a-half whorls.

Daudebardia novoseelandica, Pfeiffer. (?) The animal has no locomotive disc, but a specimen long preserved in spirit showed a central longitudinal groove on the foot. There is no jaw. Teeth 15–0–15. There are about 35 transverse rows of teeth, which form an obtuse angle of about 100°, salient posteriorly. (Pl. IV., fig. M.) The breadth of the radula is .16 inch, and its length about three times as much. Teeth aculeate, with a central process of attachment. The apices of the teeth belonging to the five inner and two outer rows are simple, but those of the sixth to thirteenth rows are barbed, looking like the fluke of an anchor seen in profile. (Pl. III., fig. E.)

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Pulmonate Mollusca.

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The specimen from which the figures were taken was collected by Mr. T. Kirk, at Waiuku, in the Lower Waikato district. The animal was without its shell, but from the mark on the body it was easy to see that the shell was pauci-spiral, and on the hinder part of the body. As Daudebardia novoseelandica came originally from the Waikato, I presume that this is the same species; but while the shape of the shell is that of Daudebardia, the teeth appear to belong to Testacella.

Paryphanta busbyi. There is no jaw. The radula is about an inch in length, and .4 inch in breadth at the anterior end, tapering to a point posteriorly, with about 104 transverse rows of teeth, the rows forming an obtuse angle of about 130°, salient posteriorly (Pl. IV., fig. L). The teeth are 50–0–50. They are all aculeate, and similar, with simple bevelled tips (Pl. IV., fig. A). The first five laterals are small. From the sixth they gradually increase in length to about the thirty-fifth, and then get smaller.

This description is taken from a specimen, very well preserved in spirit, kindly given me by Mr. T. F. Cheeseman. The whole of the animal, including the sole of the foot, is dark blue-black. The upper surface is covered with rather large, flat, granulations. The foot is narrowed in front and behind, the margin produced, and waved. I could see no sign of a caudal gland.

It is evident that this genus should be placed in Vitrininæ, near Daudebardia.

Helix fatua, Pfeiffer. The jaw is arcuate, slightly attenuated at the ends, composed of about twenty imbricating plates; its outer surface is rough, with horny hair-like papillæ, which form a fringe round the lower margin. (Pl. III., fig. N.)

The radula is .007 inch in breadth. The transverse rows of teeth form an obtuse angle of about 200°, salient posteriorly. (Pl. IV., fig. N.) The teeth are 20–1–20. In all the reflexed part is very small. The central tooth has a single cusp, bearing a cutting point, with square projecting shoulders at its base; the base of attachment is rectangular, three times as long as broad, and two-thirds of its length projecting beyond the cutting point of the reflexed portion. All the lateral and marginal teeth are bicuspid, the cusps being equal, and each bearing a cutting point. The cusps gradually diminish in size outward until they can hardly be recognized in the outer marginals. The base of attachment of the inner teeth is rectangular, but becomes oblique in the outer laterals, and then gradually rectangular in the marginals; its length gradually decreases from the central row outward.

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The specimen figured came from Dunedin. It resembled the description and size of H. fatua, except that it was slightly spotted with rufous. It differed from H. zealandiæ, in being only sub-carinated. Its remarkable dentitition and jaw of course take it out of Helix. Probably it must be formed into a new genus, but I have not the necessary books for determining this point.

Limax Agrestis, Linnæus. I have no doubt now that my L. molestus is this species. The differences that I pointed out were the non-obliquity of the keel, which Mr. Binney says is quite inconstant, and the different shape of the ovo-testis. In this latter point I had not compared our slugs with European examples, but trusted to Mr. Newton's figure in the Quar. Jour. Micros. Science, N.S., vol. 8, p. 26; as, however, I find that the teeth are quite identical, I drop my name. The radula has 93 transverse rows of teeth, each row having 42–1–42. On Pl. III., fig. H., I give figures of a central, lateral, and marginal tooth, from one of my type specimens from Dunedin. The jaw is figured at fig. P.

Milax Antipodum, Pfeiffer. Jaw very slightly arcuate, with a slight median projection. (Pl. III., fig. Q.)

Radula .06 inch in diameter, and about two and two-third times as long, with about 92 transverse rows of teeth, which are slightly curved, the convexity being posterior. (Pl. IV., fig. s.) Teeth 40–1–40, of which 16 are laterals. The central tooth has a single cusp, the shoulders of which slope gradually into the base, and each carries a small cutting point. In the laterals the shoulders are more strongly marked, but the inner one gradually dies away and its cutting point gets very minute, until on the 13th or 14th tooth it cannot be seen, and the outer one is very small. In the 15th and 16th teeth the median cutting point rapidly increases, and approaches in size the aculeate marginal teeth. (Pl. III., fig. G.)

The specimen figured came from Dunedin, but I have also found it in the bush at Governor's Bay, Banks Peninsula.

Milax Emarginatus, Hutton. The jaw is narrow, nearly straight, with a slight median projection. (Pl. III., fig. s.)

The radula is .07 inch in diameter, with about 90 transverse rows of teeth, which are slightly curved, the convexity being posterior. Teeth 46–1–46, of which about 16 are laterals. These teeth differ from those of M. antipodum in having the cutting points much larger; the shoulders in No. 1 lateral are much more sloping, and the shape of the reflexed part of No. 14 is quite different. (Pl. III., fig. I.) I have figured the teeth of a small specimen from Dunedin.

Arion Fuscus, Muller. My A. incommodus is, I think, identical with this species, of which I had seen no description until this year. I have only seen it from Dunedin. The ribbed jaw is figured in Pl. III., fig. R. The

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teeth are 34–1–34, of which about 12 are laterals, and there are about 111 transverse rows. I have figured, from a Dunedin specimen, some of the teeth on Pl. III., fig. K.

Onohidella Patelloides. No jaw. Radula is .17 inch in length, and .1 inch in breadth at the posterior end, tapering to a point anteriorly. There are 84 transverse rows of teeth, which form an obtuse angle of about 125°, salient anteriorly. (Pl. IV., fig. R.) Teeth 130–1–130. The central tooth is tricuspid, the median cusp with a short pointed cutting point; the side cusps with broad incurved cutting points. The laterals pass gradually into the marginals; they all have a single cusp bearing a blunt cutting point. From the anterior end a curved process of the base projects forward; this is short in the rows near the centre, and gets longer toward the margin. (Pl. IV., fig. B.)

Bulimus Gibbosa, Gould (Physa)? These specimens were given me by Mr. J. D. Enys, and came from the Broken River. The spire is very short, the whorls are rounded, without any trace of keel; the columella plait obsolete. The shells are olive green in colour, L .3; B .17. The apex in all is eroded, but the whorls are apparently four. I am doubtful whether this is Gould's gibbosa, but it may remain under this name for the present, until the species are better known.

Animal. The edge of the mantle is simple, and not reflexed over the shell. Tentacles long and filiform, with a rounded lobe at their outer bases. Eyes sessile at the inner bases of the tentacles. Foot short and rounded behind, truncated and not expanded in front. Rostrum bilobed. Pl. IV., fig. v.) The animal is yellow-brown, minutely speckled with greenish brown. It walks by jerks. The eggs are in transparent capsules attached to stones, etc., usually three or four together, arranged in a single layer.

Dentition. The upper jaw is simple, arcuate, and attenuated suddenly at each end; it is transversely striated. The lower jaw is membraneous, soft, and yielding. (Pl. IV., fig. T.) The radula is .07 in length, and .03 in breadth; it is parallel-sided and rounded at the anterior extremity. There are 126 transverse rows of teeth, curved slightly forwards. (Pl. IV., fig. Q.) The teeth are 27–1–27. The central tooth has its base longer than broad, and with parallel sides; the reflected portion has a single cusp, which bears two small cutting points, variable in shape and size. There are about ten laterals on each side; they have a single cusp, which bears a tridentate cutting point. In the marginals the cutting point has numerous denticulations, and the reflexed portion gets longer. (Pl. IV., fig. C.)

The simple mantle margin, not reflected over the shell, and the sinistral twisting of the shell itself, would place this species in Bulimus; but the shell is not elongated, the aperture is not narrow, and the foot is not dilated

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anteriorly. Perhaps this and the next species should form a distinct genus; certainly they do not belong to Physa. I would propose that Adams' subgenus Ameria be retained for them.

Bulimus Variabilis, Gray (Physa). Animal and radula like B. gibbosa, but with only 112 transverse rows of teeth. Teeth 18–1–18, of which seven or eight are laterals. Generally the teeth are similar to those of B. gibbosa, but the base of the central tooth is as broad as long at its posterior margin, and the reflected portion is simply convex anteriorly; the teeth are larger and coarser, and the outer marginals are not so long. (Pl. IV., fig. D.)

This description is taken from the common species found in the neighbourhood of Christchurch. It is very variable in shape, the whorls being either rounded or slightly flattened behind; the body whorl usually bears indications of a keel, formed by a single row of fine short hairs, but sometimes this is absent. The spire is more produced than in B. gibbosa, and the whorls are not so much flattened behind as in P. mæsta. Whorls 4; columella plait distinct.

Probably the other species of Physa described from New Zealand will all be found to belong to the same genus.

Latia Neritoides. I have to thank Mr. T. F. Cheeseman for numerous specimens, preserved in spirit, collected by him in Lake Pupuke, near Auckland. I have never seen the genus in the South Island.

Animal. The eyes are at the outer bases of the tentacles, which, in spirit specimens, are short, incurved, and transversely ringed. (Pl. IV., fig. U.)

Dentition. There is no jaw. The radula is .08 inch in length, and .04 inch in breadth, the sides nearly parallel. There are 30 transverse rows of teeth, which form an angle of abont 115°, salient anteriorly. (Pl. IV., fig. P.) The teeth are 27–1–27. The central tooth is small, the reflected portion half the length of the base, and bicuspid, but apparently without any cutting points. The laterals are all nearly alike, and increase in size outwards to about the sixteenth, and then diminish. The base is constricted in the middle, and the outer side has two teeth near the posterior end. The reflected part is oblique to the base, single cusped, with a rounded cutting point. (Pl. IV. fig. E.)

The position of the eyes, outside the tentacles, would appear to take Latia out of the Limnæidæ, and the absence of a jaw, as well as the arrangement of teeth on the radula, are other characters by which it is distinguished. It may form the family Latiidæ.

Amphibola Avellana. In a paper on the anatomy of this species, in the “Ann. Nat. Hist.” for 1879, I briefly described the dentition, but the description is not sufficiently accurate, and I have inadvertently stated that

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Pulmonate Mollusca.

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the teeth point forward. There is no jaw. The radula has 44 transverse rows of teeth, which form an angle of about 105°, salient anteriorly. Pl. IV., fig. o.) The teeth are 29–1–29. The central tooth has five or six denticles on each side of the median cusp, and on the right side the margin is finely but variably denticulated; the median cusp bears a single blunt cutting point. On each side there is a single lateral tooth, which, however, is often divided into two; it is very variable in shape, but more or less quadrate, with a variously denticulated cutting point. Outside this the teeth are all aculeate, and increase in length toward the margin. (Pl. IV., fig. F.)

In the paper already mentioned, I stated that I had failed to discover how the oviduct was connected with the albumen gland, but on the 5th September, 1879, I found a specimen in which the oviduct was distended with ova, and which showed clearly that my supposed accessory gland is the commencement of the oviduct. The sketch on Pl. IV., fig. w, is from this specimen.

Lymnæa Stagnalis. This species has been introduced intentionally into the river Avon at Christchurch, and is now abundant below the Acclimatization Gardens.

Explanation Of Plate III.

Note.—The numbers under the teeth give the longitudinal row of that tooth from the centre. Teeth belonging to the central row have no number.

A.

Patula coma. Teeth × 480.

B.

Patula hypopolia. Teeth × 480.

C.

Patula igniflua. Teeth × 480.

D.

Placostylus bovinus. Teeth × 150.

E.

Daudebardia novoseelandica. Teeth × 80.

F.

Helix fatua. Teeth × 480.

G.

Milax antipodum. Teeth × 280.

H.

Limax agrestis. Teeth × 280.

I.

Milax emarginatus. Teeth × 280.

K.

Arion fuscus. Teeth × 480.

L.

Patula coma. Jaw × 80.

M.

Patula igniflua. Jaw × 40.

N.

Helix fatua. Jaw × 80; a end of jaw further enlarged.

O.

Placostylus bovinus. Jaw × 15.

P.

Limax agrestis. Jaw × 15.

Q.

Milax antipodum. Jaw × 15.

R.

Arion fuscus. Jaw × 35.

S.

Milax emarginatus. Jaw × 15.

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Explanation Of Plate IV.
A.

Paryphanta busbyi. Teeth—a ordinary view; b from above; c side view × 80.

B.

Onchidella patelloides. Teeth—a central tooth; b lateral tooth; c marginal tooth; d side view of marginal tooth × 480.

C.

Bulimus gibbosa. Teeth × 480.

D.

Bulimus variabilis. Teeth × 480.

E.

Latia neritoides. Teeth × 280; a base from behind.

F.

Amphibola avellana. Teeth × 280; a central: b first lateral; c and d marginals.

G.

Patula coma. Portion of radula × 30.

H.

Patula hypopolia. Portion of radula × 30.

I.

Patula igniflua. Portion of radula × 30.

K.

Placostylus bovinus. Radula × 2.

L.

Paryphanta busbyi. Radula, natural size.

M.

Daudebardia novoseelandica. Radula, natural size.

N.

Helix fatua. Portion of radula × 70.

O.

Amphibola avellana. Radula × 15.

P.

Latia neritoides. Radula × 15.

Q.

Bulimus gibbosa. Radula × 15.

R.

Onchidella patelloides. Radula × 6.

S.

Milax antipodum. Radula × 6.

T.

Bulimus gibbosa. Jaw × 30.

U.

Latia neritoides. Head of animal. (Spirit specimen.)

V.

Bulimus gibbosa. Animal—a from above; b from below.

W.

Amphibola avellana. Reproductive organs—a hermaphrodite duct; b albumen gland; c oviduct; d vas deferens.

Note.—The dotted lines on the radulas show the direction of the transverse rows of teeth.