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Volume 72, 1942-43
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Some Eocene Mollusca from New Zealand.

[Read before the Wellington Branch, August 18, 1942; received by the Editor, August 19, 1942; issued separately, December, 1942.]

Most of the specimens described below were collected from Hampden Beach during the geological survey of Moeraki Subdivision, North Otago, by Mr D. A. Brown, in 1937–38. Some, also from Hampden, were collected many years ago by Dr P. Marshall, and lodged with the Geological Survey. A full, revised list of the Hampden molluscan faunule will appear in the Geological Survey Bulletin of the district.

The three species from the Opua River, Kakahu, South Canterbury, were collected in 1933 by Dr P. B. Maling, now of London. One of these, Keilostoma malingi n.sp. is of outstanding stratigraphic interest, as it provides a direct link with the Eocene of the Paris and London Basins.

All the holotypes of the new species here described are in the N.Z. Geological Survey collection.

Nuculanidae.

Nuculana (Pseudoportlandia) tahuia n.sp. (Plate 23; Figs. 1, 2.)

This species is closely related to N. solenelloides (Marshall) from Hampden. It differs in being considerably smaller, and in having a relatively greater height compared with the length. This means that the umbos are narrower and more prominent, and the dorsal margins descend more steeply. The posterior margin is narrow and not so abruptly truncated.

Height, 12 mm.; length, 18.2-mm.; inflation (1 valve), 4.5 mm.

Locality: McCullough's Bridge. Tahuian Stage.

When describing his Sarepta solenelloides, Marshall (1919, p. 233) stated: “It may be that this is the species recorded by Hutton from these beds under the name Malletia funiculata, but his specimens seem to have disappeared, and the name is a nomen nudum.” Since N. solenelloides is one of the commonest species at Hampden, there is little doubt that this is the shell Hutton included in his M. funiculata. The specific name funiculata, however, must be recognised, because Hutton gave a reference to Zittel's figure of a Nelson shell (wrongly identified as the Recent Solenella australis Q. & G. = Neilo). Topotypes from the Cliffs, Nelson, resemble N. awamoana Fin., but are only about half the size. The locality, however, does not provide good specimens, so it will be best, until more material is available, to retain awamoana as at present, and keep funiculata for the Nelson shells and such as closely agree with them.

The following, then, must be added to our Tertiary molluscan fauna:—

Neilo funiculata (Hutton).

1864. Solenella australis Quoy and Gaimard, Zittel, Novara Exped., Geol. Theil, 1 Bd., 2 Abt., p. 47, pl. 13, figs. 2a, b (not of Q. and G.).

Holotype: Natural History Museum, Vienna.

Locality: The Cliffs, Nelson. (? Hutchinsonian Stage.)

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Nuculana (Jupiteria) hampdenensis n.sp. (Plate 23; Figs. 4, 6.)

Shell resembling N. leachi Marw. and probably directly ancestral. It differs in having a more concave posterior dorsal margin, so that the flat escutcheon is not seen when viewed side on. The sculpture is slightly finer than that of leachi, but similar concentric grooves due to growth pauses are present.

Height, 3.5 mm.; length, 5 mm.; inflation (1 valve), 1.3 mm.

Locality: Hampden Beach. (Bortonian Stage.)

N. hampdenensis is much closer to N. leachi than to N. parleachi Laws, which is easily distinguished by its higher posterior beak.

Poroleda antiqua n.sp. (Plate 23; Fig. 5.)

Shell rather small, differing from lanceolata in having a more concave and descending posterior dorsal margin, and a slightly more descending anterior dorsal margin, causing the umbo to be more prominent. The ventral margin is not so regularly arcuate, being flattened posteriorly so that the posterior beak is slightly constricted.

Height, 3 mm.; length, 8.5 mm.; inflation (1 valve), 1 mm.

Locality: Hampden Beach. (Bortonian.)

The hinge has not been clearly seen, but it appears to agree with the Recent shell. Iredale separated the Recent shells as perturbata from the Pliocene lanceolata without adequate grounds. The differences of proportion given by Finlay (1926, p. 445) do not seem to the writer established. Some specimens of lanceolata in the Geological Survey collection from Kai Iwi have a length rather more than three times their height. Consequently perturbata sinks into the synonymy of lanceolata.

Genus Ovaleda Iredale, 1925.

Genotype (original designation): Sarepta? tellinaeformis Hedley, Recent, New South Wales.

Ovaleda constricta n.sp. (Plate 23; Fig. 3.)

Suboval, subequilateral, dorsal margins descending in a regular curve, ventral margin only slightly curved, valves compressed. Surface with extremely fine, spaced, concentric ridges.

Height, 8 mm.; length, 10 mm.; inflation (1 valve), 1.5 mm.

Locality: Hampden Beach. (Bortonian Stage.)

This species is the Sarepta obolella (Tate) of Marshall's list (1923 p. 117). From the Australian shell the New Zealand one differs in being larger, stronger and relatively much less inflated. The outlines too, differ markedly, the long, gently curved, ventral margin of constricta, contrasting with the strongly convex, ventral margin of obolella.

Arcidae.

Bathyarca bellatula n.sp. (Plate 23; Figs. 14, 15.)

Shell very small, highly inequilateral beaks at anterior third Hinge straight, nearly as long as the shell. Sculpture of about 30 narrow high radial ribs, with wider, flat interspaces, some of which on the middle and anterior of the disc develop a thin interstitial rib; both ribs and interspaces are crossed by thin, distant concentric ridges, which are not so high as the ribs except near the dorsal margin. Hinge with five anterior and 10 posterior teeth, the distal ones oblique, the medial ones very short and vertical. Shell margin crenulate within.

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Height, 2.75 mm.; length, 3.6 mm.; inflation (1 valve), 1.2 mm.

Locality: Hampden Beach. (Bortonian Stage.)

In his valuable revision of the generic divisions of the Arcidae, P. W. Reinhart (1935, p. 36) has correctly pointed out that the two New Zealand fossils Microcucullaea crenulifera and M. pectinata Marwick, 1931, are closer to Bathyarca than to Microcucullaea. His placing of Microcucullaea as related to Bathyarca rather than to Cucullaea is also justified by a general consideration of the hinges, sculpture and shape of these small shells.

In his table of distinguishing characters, Reinhart gives Bathyarca as having a smooth margin, but this seems to be a variable character, as regards the present scope of the genus. A great range of differences in hinge teeth is also shown, indeed it seems certain that some very distantly related species are at present included. Reinhart stated that he had not found a definite record of Bathyarca earlier than the Oligocene, apparently disregarding Cossman's suggestion, cited by Woodring (1925, p. 53), that A. lissa Bayan from the Parisian Eocene is a Bathyarca. This absence or rarity of the genus in the Eocene gives added interest to B. bellatula.

Pectinidae.

Lentipecten parki n.sp. (Plate 23; Figs. 7, 10, 13.)

Shell fairly large, almost equilateral and equivalve except for the ears. Dorsal margins slightly concave, apical angle increasing from about 110° to about 125°. Surface smooth, but having extremely fine, regular, concentric grooves, about 12 per mm. Ears subequal, relatively very long, those of the left valve with a remarkably straight dorsal margin and almost rectangular corners, those of the right valve with a strongly but irregularly serrate dorsal margin. Right anterior ear with a moderately deep byssal notch which, however, does not form a radial groove or ridge. Both ears of the right valve set on a plane oblique to that of the disc and separated from it by a step or ramp which gets rapidly broader distally. Internally, the hingemargin is narrow, and quite intersected by the resiliary pit.

Height, 55 mm.; length, 57 mm.; inflation (1 valve), 8 mm.

Localities: Hampden Beach (type); G.S. 2572, Waihao Downs; G.S. 164, Greensands, Kakahu (Bortonian Stage); G.S. 2873, Ten Mile, Greymouth, near top of Island Sandstone (? Tahuian).

This shell is, of course, very like the widespread Miocene L. hochstetteri (Zitt.), and has been so identified (under the synonym P. huttoni Park) in most lists of Hampden mollusca. The two species are easily distinguished by their ears. In the left valve; the ears of hochstetteri (Plate 23, fig. 12) have a much shorter dorsal margin having, at its extremities, obtuse angles of about 120°. The long, straight dorsal margin of the ears of L. parki (Plate 23, fig. 13) forms with the anterior and posterior vertical margins an approximate right angle. In the ears of the right valve the dorsal margin is straighter and the distal angles are rounded and obtuse in hochstetteri (Plate 23, fig. 9), but they are sharp and subrectangular in parki (Plate 23, figs. 7, 10). Further, the bysal notch of parki is considerably deeper, but the shallow sinus of hochstetteri forms a low radial bulge.

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If the ears are missing difficulty may be met in identifying the disc of parki as distinct from hochstetteri, but the very fine regular concentric grooves are better developed in parki. Another item for distinguishing parki is the well defined step or ramp on the right valve, separating the ear from the disc.

The holotype of L. waihaoensis consists of a fairly complete, ribbed left valve and a smooth right valve with much damaged ears. These were collected by J. A. Thomson, together, and appeared to belong to one individual. If the relationship of the valves is as supposed, then parki must be closely related to waihaoensis, because their right valves are indistinguishable. No ribbed left valves have been found at Hampden, though smooth ones are not uncommon; but at Waihao Downs both smooth and ribbed left valves occur. Further, there are differences in the strength of the ribs. It may be that a gradation exists at Waihao between the smooth and the ribbed, but more material is required to throw light on this question. The absence of any ribbing on the Hampden shells justifies their systematic recognition.

Veneridae.

Marama (Hina) vaga Marwick. (Plate 24; Figs. 23, 24.)

1927. Trans. N.Z. Inst., vol. 57, p. 605.

When this species was described originally, figures were promised for the following year. Somehow, they have always escaped publication, so the writer is glad of this chance to carry out the promise, even if belatedly.

Locality: McCulloughs Bridge. (Tahuian Stage.)

Verticordiidae.

? Verticordia neozelanica (Suter).

1873. Trigonia peotinata Lamk.: Hutton, Cat. Tert. Moll. and Ech. N.Z., p. 27.

1914. Suspend: Suter, N.Z. Geol. Surv. Pal. Bull. 2, p. 38.

1915. Trigonia neozelanica Suter, N.Z. Geol. Surv. Pal. Bull. 3, p. 50, pl. 5, fig. 3.

Hutton apparently identified his single specimen with the Recent Australian Trigonia largely because the shell is pearly. No further specimens have been collected. The exterior sculpture was concealed by matrix and the umbo and hinge, as noted by Suter, are missing. When the exterior had been laid bare, Suter gave the specimen a specific name, following Hutton's generic placing without comment. He considered the shell to be a left valve, thus treating the beaks as opisthogyrous, as they should be if the shell is a Trigonid. However, the right hand side of the disc shows no modified posterior area such as is invariably present in Trigonia, but the left side has a well marked radial depression, extending from the umbo to the ventral margin. This so closely resembles the posterior depression characteristic of many pelecypods that we are almost certainly dealing with the right valve of a prosogyrous shell. Certainly, Trigonia is ruled out, but until further evidence is available, the real affinities are uncertain. The pearly shell, cordate shape, and regular, strong, radial ribs suggest the Verticordiidae, though the size is much greater than usual.

Locality: Hampden Beach. (Bortonian Stage.)

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Verticordia densicostata (Marshall).

1919. Trigonia densicostata: Marshall, Trans. N.Z. Inst., vol. 51, p. 234, pl. 16, fig. 1.

1923. Verticordia densicostata: Marshall, Trans. N.Z. Inst., vol. 54, p. 117.

This species has already been transferred by its proposer, at the suggestion of Cossmann, from Trigonia, but as this appears only in a list, it is liable to be overlooked. Here, again, we have to deal with a single specimen, so poorly preserved that even the family affinities are uncertain. It was placed under Trigonia “merely in order that it may be possible to refer to it by name. … In the meantime, it may be said that the species does not belong to any other genus of Tertiary or Recent mollusca hitherto found in New Zealand.”

The sculpture of densicostata is similar to that of the preceding V. neozelanica, but the shape does not agree so closely. Since this may be due to distortion during consolidation or movement of the beds, and since both specimens come from the same locality, it is conceivable that only one species is concerned. More specimens, however, are needed to show the true affinities of these two shells. Only one posterior fragment of what is probably densicostata was collected by the writer.

Locality: Hampden Beach. (Bortonian Stage.)

Genus Kurinuia nov.

(From the Kurinui Stream, which flows through Hampden.)

Genotype: Trigonia areolata Marshall. Bortonian (Middle Eocene).

Shell pearly, of moderate size, cordate, beaks strongly prosogyrous. Sculpture: middle and anterior of disc bearing strong, rounded, radial ribs, with narrow interstices; posterior area not excavated, but with a wide, ribless space crossed by regular, low, concentric ridges, sharply defined in front by a deep furrow, and bounded posteriorly by a low, angled rib near the dorsal margin. Right hingebearing a strong, smooth, curved, pointed, cardinal tooth immediately behind the umbo, also a strong lamellate posterior lateral. Valve margins coarsely crenate.

Kurinuia areolata (Marshall). (Plate 23; Figs. 8, 11.)

1919. Trigonia densicostata: Marshall, Trans. N.Z. Inst., vol. 51, p. 234, pl. 15, fig. 1; pl. 17, fig. 1.

Although the only two specimens available for examination are somewhat broken below the beak, the damage is not so serious as to conceal the essential characters of the hinge. Dr Marshall noted the smooth cardinal tooth and the prosogyrous beaks, but considered these to be a possible Trigonid development. The single smooth cardinal in the right valve is placed on a definite hinge plate and is curved forward and upward to a point rather like Corbula. There is no sign of external ligamental nymphs such as are present in the Trigoniidae, the ligamental groove being internal and running between the posterior lateral tooth and the dorsal margin. Further, the lunule is deeply excavated and the shell is of cordate shape.

All these characters show clearly that the shell is not a Trigonia but is related to Verticordia, from which, however, it differs in being much larger and in having a different kind of sculpture. The hingeresembles that of Haliris Dall, 1886, type Verticordia fischeriana Dall,

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and also that of Setaliris Iredale, 1930, type Verticordia setosa Hedley; but the strongly differentiated posterior area of areolata is quite peculiar. Agreement may be closer with Euciroa Dall, 1881, type V. elegantissima Dall which has weak ribbing on the posterior area, and is of large size, but which has fine, spiny sculpture. Further, the left hinge figured by Dall (Mus. Comp. Zool., vol. 12, pl. 2, fig. 1b) is evidently not the complement of the right hinge of areolata.

Incidentally, there does not seem to be much difference between Setaliris and Haliris. Iredale (1930, p. 406) gave no reason for his proposal, and as far as one can judge from the figures, setosa may well be closely related to fischeriana. Further, the “Aberrant occurrence” of Hedley's species, mentioned by Iredale (1930, p. 388) presumably referring to Hedley's remarks about the genus Verticordia characterising deeper water, does not apply to the group Haliris, for the type, fischeriana, occurs at much the same depth as the New Zealand setosa, namely, about 100 fathoms.

Calliostomatidae.

Maurea (Mucrinops) barbara n.sp. (Plate 24; Fig. 16.)

Shell rather small for the group, conic, sides straight, body-whorl bluntly angled at the periphery, base flattened, concave. Sculpture: spire-whorls with five strongly moniliform spirals differing somewhat in strength, the lowest close to the suture and weak. The highest spiral bears about 20 beads per whorl, and the others from 25 to 30. Base with 8 relatively broad and low spirals separated by wider interspaces, the outer three bearing a weak secondary thread Growth lines strongly marked.

Height, 14 mm.; diameter, 13 mm.

Locality: Opua River, a quarter mile below Gorge Bridge, Kakahu (Bortonian), P. B. Maling coll.

This species is characterised by its very coarse sculpture.

Rissoinidae.
Genus Keilostoma Deshayes.

1850. Traité élém. Conch., Atlas, p. 46. = Paryphostoma Bayan, 1873. Genotype (by monotypy): Melania marginata Lamk. (= Bulimus turricula Brug.) Lutetian, Paris Basin.

Keilostoma malingi n.sp. (Plate 24; Figs. 17, 18.)

Shell rather small, turriculate, imperforate. Protoconch not preserved on any of the specimens. Whorls with almost straight sides, suture plainly but not strongly marked, faintly staging the spire. Sculpture of flat, imbricate bands also faintly staging the spire, six on early whorls increasing to seven on later ones; body-whorl with 10 or 11 broad bands and a few narrow ones anteriorly. Aperture, entire, narrowly channelled posteriorly, broadly subtruncate anteriorly; peristome continuous. Outer lip gently convex, slightly reflexed and thickly callused, callus growing forward considerably. Inner lip thickly padded.

Height (incomplete), 12.5 mm.; diameter, 4.3 mm.

Locality: Opua River, a quarter mile below Gorge Bridge, Kakahu (Bortonian), collected by P. B. Maling.

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K. malingi rather closely resembles the French and English Eocene K. minus (Desh.) in size, shape and sculpture, differing in having a straighter outline, slightly broader spirals, weaker growth lines and a greater spread of callus on the base. It agrees much more closely with minus than with any of the three Cretaceous Indian species, substriatum, subulatum, and politum. It is probably, therefore, directly related to the European species and so forms a useful link in connecting the Bortonian stage with the Eocene.

Cox (1931, p. 47) has described a Keilostoma subturricula from the Laki (Eocene) of India, but it was formerly identified as the European turricula Brug., and is not so close to malingi as is minus.

The generic term Paryphostoma was used for this shell by Finlay and Marwick (1940, p. 87), following Cossmann (1921, p. 70) who considered Keilostoma preoccupied by Chilostoma Fitz., 1833. Sherborn also cites a Cheilostoma Diesing, 1850, that is even closer in form, but may not be earlier. On reconsideration, the writer has decided, in view of the vagueness of the rules on this subject, to use the older name, Keilostoma.

Naticidae.

Friginatica haasti (Marwick). (Plate 25; Fig. 31.)

1924. Natica (Carinacca) haasti Marw., Trans. N.Z. Inst., vol. 55, p. 554, pl. 56, fig. 8.

The finding of a fine large specimen of this rather rare species, measuring 13 mm. by 13 mm. is worth recording. Study of this shell indicates that the generic position should be changed from Carinacca to Friginatica. Although the basal limb resembles that of Carinacca, the globular shape, the deeply impressed, almost channelled suture, and the shape and disposition of the parietal callus all suggest relationship to Friginatica.

Cassididae.

Galeodea geniculosa n.sp. (Plate 24; Fig. 25.)

Shell similar to the Miocene G. apodemetes Marw. and probably directly ancestral; differing in having a concave, transverse shoulder. Consequently the shoulder tubercles are higher set. The sides of the spire-whorls are concave and more sloping than those of apodemetes, which are almost cylindrical. Sculpture of body-whorl almost the same in the two species, except that on the new species the primary spirals are better defined from the secondary and tertiary ones in the interspaces, especially on the base. An infra-sutural band is present, puckered by strong growth ridges, and resembling that of Euspinacassis. The parietal and columellar callus is closely applied to the body at its outer edge and does not project as in the Miocene descendant; also it is more wrinkled within.

Height, 39 mm.; diameter, 27 mm.

Locality: Hampden. Bortonian Stage.

All of the specimens are incomplete and distorted, the true diameter was less than this by several millimeters.

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Ficidae.

Priscoficus alectodens n.sp. (Plate 25; Figs 33, 34.)

Shell of moderate size, thin and fragile. Spire-whorls staged, with a wide, slightly concave shoulder and short, slightly concave, sloping sides. Body-whorl contracting rapidly on the base to a long, narrow canal which is not notched anteriorly. Sculpture: the spire-whorls bear sharp tubercles on the shoulder-angle, about 20 on each of the early whorls but decreasing on later ones to 18, 16 or even fewer. Body-whorl having three well-spaced rows of strong, sharp, laterally extended tubercles, the middle row forming the periphery. The whole surface marked by spiral cords with wide, flat interspaces, several times the width of the cords. The spirals differ greatly in strength, some, especially each one on the tubercled bands, being very strong, others can scarcely be seen. Between the suture and the top row of tubercles there are four spirals on earlier whorls, but the number on the adult is uncertain. Between the top and middle tubercled bands are four spirals on the immature specimen and seven on the larger one, the top one and the lowest three being much weaker than the others. Between the middle and the bottom tubercled band are three strong cords, with a weak to faint thread in all interspaces except the second lowest. Between the lowest band and the anterior end of the shell are some 29 spirals, the top six alternating markedly in strength; the next four, that is, those about the junction of the base and neck, are all strong; and the next 10 on the neck alternate in strength. Anteriorly are about nine, closely placed, wavy threads.

Height, 47 mm.; diameter, 25 mm. (body fragment, holotype).

The dimensions of a complete adult probably about 65 × 35 mm.

Locality: Hampden Beach. (Bortonian Stage.)

This is probably the species from Kakahu listed by Finlay and Marwick (1937, p. 119, pl. 16, fig. 18) as Priscoficus n.sp. A. Apology may be due for naming such poor material, but the sculpture of the body-whorl is clearly shown and is quite distinctive.

Epitoniidae.

Cirsotrema kuriensis n.sp. (Plate 24; Fig. 21.)

Shell moderate to small for the genus. Sculpture consists of very strong, high axial ribs, 10 per whorl, separated by considerably narrower, flat interspaces, except on the early whorls where the ribs are narrower than the interspaces. Both ribs and interspaces are crossed by seven strong, spaced, spiral cords which are weaker, however in the interspaces. The spiral interspaces and the backs of the ribs bear numerous, close, spiral threads about 4 per interspace. The crests of the ribs, between the spiral cords have many close, sharp vertical growth-ridges.

Height, 28 mm.; diameter, 12 mm.

Locality: Hampden Beach. (Bortonian Stage.)

This species combines features of both lyrata Zittel and caelicola Finlay. The thick ribs surpass those of caelicola but are about the same in number, and the spiral cords resemble those of lyrata, under which name the shell has generally appeared in Hampden lists.

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Eulimidae.

Niso basiglobosa n.sp. (Plate 24; Figs. 19, 20.)

Shell of moderate size, narrowly conic. Protoconch eroded in the single specimen. Whorls 12, height of each about three-eighths diameter, sides flat. Surface somewhat pitted by weathering, growth lines weak, a number of oblique, slightly concave growth pauses well defined. Suture inconspicuous. Body-whorl slightly over one-third total shell height, regularly rounded on the periphery. Umbilicus moderately large, its walls curved and merging gradually into the base without any ridge. Aperture relatively short, with just a suggestion of an anterior beak. Outer and inner lips thin, parietal wall without callus.

Height: 17 mm.; diameter. 6.5 mm.

Locality: Opua River, a quarter mile below Gorge Bridge, Kakahu (Bortonian), P. B. Maling coll.

The absence of a ridge bounding the umbilicus and the rounded periphery show that this shell is off the main line of Niso descent. Cossman and Peyrot's N. degrangei from the Helvetian of Aquitaine is similar though it has a sub-angulate periphery, straighter umbilical walls and, therefore, a better defined beak. N. angusta Desh. from the Paris Basin Eocene has a rounded periphery but a smaller umbilicus. Cossman and Peyrot (1917, p. 286) stated moreover that the protoconch of degrangei has a heterostrophic nucleus. This confirms the evidence of the other characters that this species does not belong to Niso restricted, and perhaps not to Niso even in a wide sense. It should at least be subgenerically separated. Whether angusta or the new species belongs to this group or to another one cannot be decided until the protoconchs are known.

Fasciolariidae.

Zexilia hampdenensis n.sp. (Plate 24; Fig. 22.)

Shell larger than Z. waihaoensis and having somewhat higher, less convex whorls. The ribs are narrow, having rather a sharp ridge and so being triangular in cross section; they are also more numerous, the last whorl having 28, and the penultimate 20. As in waihaoensis, the spiral cords number six per whorl, with a seventh appearing in the lower suture. They are strong, but relatively narrow, with wide interspaces, and are raised into tubercles where they cross the axials.

From Z. tenuilirata Laws and Z. submarginata Laws, Z. hampdenensis is easily separated by its more convex whorls, stronger spirals, and differently curved axials.

Height, 22mm.; diameter, 7 mm. (spire only). Paratype, 33 × 7 mm.

Locality: Hampden Beach. (Bortonian Stage.)

Fascioplex neozelanica (Suter). (Plate 25; Fig. 28.)

1934. Marwick, Proc. Mal. Soc., vol. 21, p. 16, pl. 1, figs. 6, 8.

A single, rather distorted, but otherwise good specimen from Hampden Beach (Bortonian) probably should be included in our conception of this species, or as G. Simpson (1940, p. 413) would express it, “should be included in the hypodigm” of F. neozelanica.

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It differs from any previous members of this species seen by the writer in having only obsolete axials on the body-whorl, and so presenting a strong ficoid appearance externally.

Fascioplex browni n.sp. (Plate 25; Fig. 30.)

Shell fusiform, turreted, imperforate; spire two-thirds height of aperture and canal. Whorls strongly angled, base contracting rather quickly to (apparently) a straight canal. Sculpture: spire whorls with nine, body whorl with ten strong, vertically compressed, sharp tubercles on the shoulder angle. Although compressed vertically, the tubercles are set on axials of moderate strength but somewhat irregular definition. Shoulder with two weak spiral threads also with traces of an interstitial and of other spirals. Below the shoulder are six strong, distant imbricate cords, mostly with two or three weak, well spaced secondary spiral threads. The whole surface bears strong laciniate, sinuous growth-ridges, about one per millimeter, quite trophonid in appearance. Sutures appressed, high up on the preceeding whorl. Columella having at its base two strong, oblique plaits, the lower somewhat stronger, between them a well defined channel.

Height, 35 mm.; diameter, 24 mm.

Locality: G. S. 1988. Greensands, in abandoned rail cutting, Waihao Downs.

This species resembles F. liraecostata in sculpture but is easily distinguished by the high, staged spire. Also the canal, though broken, appears to have been straight, and there is no sign of any fasciole.

?Fascioplex n.sp. (Plate 25; Fig. 32.)

A fragment of the body whorl of a shell shows in section a spiny sculpture, in part at least, set on a muriciform varix. The columella has, at its junction with the long, slightly curved canal, two strong plaits, the lower somewhat stronger and the two forming a narrow, deep, oblique channel. These columellar folds agree closely with those of Fascioplex but the canal appears to be much longer and narrower. The sculpture, as far as can be seen, suggests the Muricidae. The shell is apparently rare, as only the one fragment has been seen; and a certain placing of it must wait for further specimens. The species previously described, Fascioplex browni, forms, with its sharply raised trophonid ridges a kind of link between this peculiar Muriciform shell and Fascioplex.

Falsicolus altus (Marshall). (Plate 25; Fig. 27.)

1919. Fusinus altus Marsh. Trans. N.Z. Inst., vol. 51, p. 229, pl. 16, fig. 5.

Judged from more than a dozen fragmentary specimens, F. altus appears to differ consistently from bensoni Allan which was synonymised with it by Finlay (1930, p. 260). The ribs are more numerous in altus, being from 11 to 12 per whorl, against the nine of bensoni. Except on the last whorl or so, the ribs of altus are not tuberculed as in bensoni, so that the spire whorls are convex instead of angled. Certainly the species are closely related, and F. solidus (Suter) is perhaps intermediate between the two. Of course the whole question of what is a species immediately arises, but it cannot be adequately discussed here. However, it may be stated that the species envisaged is a convenient group of individuals sufficiently interrelated to maintain a reasonably uniform set of genetic characters.

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Owing to the lack of good specimens, F. altus has not been adequately figured. The figure here supplied still leaves much to be desired, but it will serve to differentiate altus from bensoni.

Locality: Hampden Beach. (Bortonian Stage.)

Mitridae.

Genus Compsomitra nov.

Genotype: Compsomitra incisa n.sp. Bortonian (Middle Eocene).

Shell rather small, fusiform, spire higher than aperture. Protoconch of about two whorls, with a large, bulbous apex. Whorls convex, body contracted quickly on the base to a long, straight neck without a fasciole. Sculpture of numerous, strong axial ribs, triangular in cross section, not defined from the interstices. The whole surface bears regular spiral grooves, separating flat cords on the sides of the whorls, but round cords on the base. Columella with three strong folds, and a fourth very weak one anteriorly.

The Mitrids have had about 50 subdivisions proposed, so that one hesitates to add to the number. However, as far as the writer can determine, none of the proposed groups appears to be at all close to the Hampden shell, consequently a new division has to be set up for it.

Compsomitra is perhaps nearest related to some of the species at present included in Costellaria Swainson, such as borsoni and recticostellata Bellardi from the Miocene of the Vienna Basin. The type of Costellaria, M. rigida Swainson, is, however, a different-looking shell. It has a long, sub-cylindrical body, with a very short canal, strongly notched and fascioled. Iredale (1929, p. 346) has indicated the need for further study in the group. His Mitropifex shows some points of agreement with Compsomitra in sculpture and convexity of whorls, but the high spire and twisted canal are different.

Compsomitra incisa n.sp. (Plate 25; Fig. 29.)

The axials number about 21 per whorl, they are strongly arched so that the outer lip had a sigmoid outline. The penultimate whorl has 10 flat spiral threads, the posterior thread being twice as broad as the others and so forming an infrasutural border. The outer lip of the single specimen has been broken off, but there is no sign of internal lirae. The growth lines indicate that there was no anterior sinus to the canal.

Height, 16 mm.; diameter, 6.5 mm.

Locality: Hampden Beach. (Bortonian Stage.)

Columbariidae.

Coluzea aff. climacota (Suter).

1917. Fusinus climacotus Suter, N.Z.G.S., Pal. Bull. No. 5, p. 21. pl. 3, fig. 12.

1926. Coluzea, Finlay, Trans. N.Z. Inst., vol. 57, p. 407.

A large spire (26 mm.) from Hampden Beach (Bortonian) has only two, instead of three, primary spirals on the shoulder, with a weak interstitial. A small, imperfect specimen (22 mm.) from the same place has three weak spirals on the shoulder. The material is not good enough to make sure, but it suggests that the Hampden form is separable from climacota s.str.

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Figs. 1, 2.—Nuculana (Pseudoportlandia) tahuia n.sp. Holotype, × 2.
Fig. 3.—Ovaleda constricta n.sp. Holotype, × 2 ½.
Figs. 4, 6.—Nuculana (Jupiteria) hampdenensis n.sp. Holotype, × 6.
Fig. 5.—Poroleda antiqua n.sp Holotype, × 4.
Figs. 7, 10.—Lentipecten park n.sp. Paratypes, right valves, × 1.
Figs. 8, 11.—Kurnuia areolata (Marsh.) n.gen. Hampden, × 2.
Figs. 9, 12.—Lentipecten hochstetteri (Zitt.) Ears of right and left valves, × 1.
Fig. 13.—Lentipecten parki n.sp. Holotype, × 1.
Figs. 14, 15.—Bathyarca bellatula n.sp. Holotype × 10

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Fig. 16.—Maurca (Mucrinops) barbara n.sp. Holotype, × 3.
Figs. 17, 18.—Keilostoma malingi n.sp Holotype, × 3.
Figs. 19, 20.—Niso basiglobosa n.sp. Holotype, × 3.
Fig. 21.—Cirsotrema kuriensis n.sp. Holotype, × 2.
Fig. 22.—Zexilia hampdenensis n.sp. Holotype, × 2.
Figs. 23, 24.—Marama (Hina) vaga Marw. Holotype, × 1.
Fig. 25.—Galeodea geniculosa n.sp. Holotype, × 1 ½.
Fig. 26.—Dentahum centenniale n.sp. Holotype, 1 ½.

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Fig. 27.—Falsicolus altus (Marsh.). Hampden, × 1 ½.
Fig. 28.—Fascioplex neozelanica (Suter). Hampden, × 1 ½.
Fig. 29.—Compsomitra incisa n.gen., n.sp. Holotype, × 2 ½.
Fig. 30.—Fascioplex browni n.sp. Holotype. × 1 ½.
Fig. 31.—Friginatica haasti (Marw.). Hampden, × 2.
Fig. 32.—Fascioplex n.sp. Hampden, showing Muricoid sculpture, × 1.
Figs. 33. 34.—Priscoficus alectodens n.sp Holotype and paratype, × 1 ½.

– 279 –

Dentalium centenniale n.sp. (Plate 24; Fig. 26.)

Shell of moderate size and thickness, rather slender, tapering only gradually, lightly curved. Apical part with 29 narrow but strong ribs rather uneven in strength, but all much narrower than the interspaces. As the shell grew, the ribs became relatively broader, so that anteriorly they are about equal in width to the interspaces. An interstital thread tends to appear in the interspaces, especially in the anterior third. Some of the earlier appearing of these became a good deal stronger. Growth lines are strongly marked throughout.

Length, 73 mm.; diameter (posterior), 2.2 mm.; (anterior), 7.5 mm.

Locality: Hampden Beach. (Bortonian.)

This Dentalium was collected at Hampden Beach (i.e., One-kakara) almost 100 years ago by Walter Mantell. (1850, Quart. Journ., vol. 6, p. 331, pl. 28, f. 15). Zittell (Novara Exp., Geol., vol. 1, pt. 2, p. 45) identified Hochstetter's Nelson specimens with the Hampden species and gave the name D. mantelli without, however, naming a type. Suter (1914, p. 32) accepted this identity, and stated that the type was in the “K.K. Hofmuseum, Vienna.” It is not clear whether this was an actual designation of type, or merely a statement based on the idea that Zittel's specimen was automatically the type. In any case, it is best taken as a designation of type. The Hampden shells, however, are easily distinguished by their narrow ribs and wide interspaces, so they deserve specific recognition.

References.

Cossmann, M., 1921. Ess. Pal. comp., vol. 12, Paris.

—– and Peyrot, 1917. Conch. Néog. de l'Aquit., tome 3 (Gastr.). Act. Soc. Linn. Bordeaux, vol. 69.

Cox, L. R., 1931. A Contribution to the Molluscan Fauna of the Laki and Basal Khirthar Groups of the Indian Eocene. Trans. Roy. Soc. Edinb., vol. 57, pt. 1, No. 2.

Finlay, H. J., 1926. A Further Commentary on N.Z. Molluscan Systematics. Trans. N.Z. Inst., vol. 57.

—– 1930. Revision of the N.Z. Shells Referred to Fusinus. Trans. N.Z. Inst., vol. 61.

Finlay and Marwick, 1937. The Wangaloan and Associated Molluscan Faunas of Kaitangata-Green Island Subdivision. N.Z. Geol. Surv. Pal. Bull. 15.

—– 1940. The Divisions of the Upper Cretaceous and Tertiary in New Zealand. Trans. Roy. Soc. N.Z., vol. 70, pt. 1.

Iredale, T., 1929. Strange Molluscs in Sydney Harbour. Aust. Zool., vol. 5, pt. 4.

—– 1930. More Notes on the Marine Mollusca of N.S.W. Rec. Aust. Mus., vol. 17, No. 9.

Marshall, P., 1919. Fauna of the Hampden Beds and Classification of the Oamaru System. Trans. N.Z. Inst., vol. 51.

—– 1923. Early Tertiary Molluscan Faunas of New Zealand. Trans. N.Z. Inst., vol. 54.

Reinhart, P. W., 1935. Classification of the Pelecypod Family Arcidae. Bull. Mus. roy. d'Hist. nat. de Belg., tome II, No. 3.

Simpson, G. G., 1940. Types in Modern Taxonomy. Am. Jour. Sci., vol. 238, No. 6.

Woodring, W. P., 1925. Miocene Mollusks from Bowden, Jamaica. Carnegie Inst. Publ. 366.