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Volume 73, 1943-44
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Some Tertiary Mollusca from North Otago.

[Read before Wellington Branch, 8th July, 1943; received by the Editor, 8th July, 1943; issued separately, December, 1943]

Most of the mollusca described or noted below were collected during the geological survey of Moeraki Subdivision, North Otago, by D. A. Brown, now of the Fleet Air Arm. Some have been in the Geological Survey collection for many years. Two necessary changes in nomenclature are included. The types of all specimens described below are in the Geological Survey collection.

The writer is indebted to Mr. N. de B. Hornibrook (now of N.Z. Expeditionary Force) for the very fine photographs of Plate 27.

Limopsis hampdenensis (Marshall).

1919. Sarepta tenuis Marshall, Trans. N.Z. Inst., vol. 51, p. 233, pl. 15, fig. 9.

1919. Limopsis hampdenensis Marshall, Trans. N.Z. Inst., vol. 51, p. 232, pl. 15, figs. 12, 13.

H. J. Finlay (1926, pp. 446, 448) stated that tenuis and hampdenensis, far from differing generically, were probably not even specifically distinct, and belonged to Limopsis. He also implied that as tenuis preceded hampdenensis on the page, it would take precedence in nomenclature.

Through the kindness of Mr. J. Grant, Director of Wanganui Museum, the writer has been able to examine both types, and can confirm the specific identity.

The single type of L. tenuis has been broken and is imperfect, but the larger of Dr. Marshall's figured types (fig. 13) of hampdenensis is well preserved. Consequently, since Dr. Finlay's statement was tentative, it seems best to select hampdenensis rather than tenuis as the specific name for these shells. Page-precedence depends on “other things being equal” (Article 28, recom. C.), and in this case “other things” are not equal.

Chlamys venosa (Hutton). Plate 25, figs 1, 2.

1873. Pecten venosum, Hutt., Cat. Tert. Moll., p. 30.

1928. Chlamys venosa (Hutt.), Marw., Trans. N.Z. Inst., vol. 58, p. 454.

This shell has not previously been figured. It was recorded by Park (1918, pp. 72 and 74) from G.S. 966, Tuffs in Oamaru Stone, Teschmakers, and G.S. 963, Tuffs in or below Oamaru Stone, Trig M., Alma. It has now been collected from Geol. Surv. Locality 2141, green tuffs, Bridge Point, 3 miles south of Kakanui. All of these localities belong to the Kaiatan Stage (Oligocene).

Janupecten subteres n. sp. Plate 25, figs 3, 7.

Shell large, subcircular, thin, flat. Sculpture between that of Janupecten and Lentipecten. Right valve with very faint, flat radial ribs on ears and on posterior and anterior flanks, dorsal and distal margins of ears strongly serrate. Left valve smooth. Surface of both valves, when well preserved with minute, regular, concentric ridges, about 7 per mm.

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Height, 93 mm.; length, 92 mm.; inflation (1 valve), 10 mm.

Localities: G.S. 2118, Greensand, Green Valley, Waihemo Surv. Dist. (type); G.S. 1314, G.S. 1821, Greensand, Wharekuri; G.S. 2108. Greensand, Te Raumaku School, Otorohanga district.

Age: Duntroonian (Upper Oligocene).

This shell is so like a Lentipecten that it is questionable whether it is really a Janupecten. The Lentipecten stock, however, extends without sculpture from the Bortonian up to the Urenuian. If subteres is an offshoot of this line, the resemblance of its sculpture to that of Janupecten (and Serripecten) becomes rather a remarkable coincidence. It seems better regarded as a further development of the Janupecten uttleyi-polemicus line that has lost almost all its radials. Convergence of two lineages through obsolescence of sculpture is more likely than through the development of a peculiar sculpture.

The smooth left valve is very like that of L. hochstetteri (Zitt.), but the anterior and posterior margins of the ears are straighter.

Genus Callolima Bartsch.

1913. Proc. U.S. Nat. Mus., vol. 45, p. 235.

Type (by original designation): Lima rathbuni Bartsch. Recent, Phillippines, 161–226 faths.

Callolima regia (Suter).

1917. Lima (Plagiostoma) regia Suter, N.Z Geol. Surv. Pal. Bull. 5, p. 70, pl. 9, fig. 1.

A specimen from G.S. 1211, Isis bed, Campbell's Beach, Allday Bay, is much more inflated than the other New Zealand specimens of this genus. It measures (1 valve), 190 mm. × 155 mm. × 45 mm., while the holotype of regia was given by Suter as 200 × 175 × 15. The Allday Bay specimen, being a single valve and occurring in a coarse matrix retains its original shape; but the other specimens seen are double valves, embedded in a fine matrix which has probably compacted a lot with the expulsion of the connate water, and caused flattening of the shells.

New Zealand species belonging to Callolima are imitata Suter. levitesta Finlay (= laevigata Hutt.), regia Suter, and a small unnamed species of Marwick, 1931.

Bartsch has given a table showing that the giant Limas (Acesta Adams and Callolima Bartsch), known from many parts of the world, all come from deep water, ranging from 150 fathoms down to 775 fathoms. However, since the Allday Bay shell is a single valve, it has probably been shifted from its original position and its significance with regard to the limestone erosion surface below is not clear.

Venericardia titirangiensis nom. nov.

1928. Venericardia martini Marwick, Trans. N.Z. Inst., vol. 58, p. 465, figs. 52, 53.

The writer is indebted to M. Andre Chavan, of Nanterre, who kindly informed him that the specific name martini is preoccupied under Venericardia by Cossmann, 1923, Journ. de Conch., vol. 68, p. 110.

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Lucinidae.

Recently A. Chavan (1937, 1938) has published a valuable essay on the classification of the Lucinidae. Although the writer does not accept all the conclusions concerning New Zealand groups, he would like here to record his appreciation of M. Chavan's work. Many more of such family revisions are needed by workers in Mollusca.

Gonimyrtea Marwick, 1929.

Chavan (1938, p. 230) has stated that Gonimyrtea (inadvertently attributed to Finlay) should be synonymized with Lucinoma Dall. The type of Lucinoma, the East American Lucina filosa Stimpson, is a large shell, some 35 mm. in diameter, with strong, distant, concentric lamellae and high, alate, dorsal, posterior and anterior areas. The lunule is not deeply sunk, and the cardinal teeth are well separated from the lunular and ligamental margins. On the other hand, the shells of Gonimyrtea are small, under 10 mm., and the sculpture consists of fine, close, concentric ridges. Thus, the two groups are easily separated on external appearance alone. The hinge of Gonimyrtea is more crowded than that of Lucinoma, and the laterals are better developed. The interior of Gonimyrtea is generally strongly striate, and the margins are sometimes weakly crenate. The three species, G. concinna Recent and Pliocene, G. discus Miocene and G. bucculenta Oligocene, form a lineage that is clearly defined and so should be systematically recognised. To the writer, it seems that the lineage is no closer, if indeed as close, to Lucinoma than it is to Loripes (= Lucinida) where Hutton first put it. True Lucinoma is, however, represented in New Zealand by the Miocene L. taylori Powell, 1935.

While discussing Lucinoma it is advisable to consider the following statement by Chavan (1938, p. 82): “‘Miltha’ ampla Hutton from the Wanganui beds in New Zealand is, according to an example in the Cossmann collection, also a Lucinoma.” Some mistake has arisen here, perhaps a wrong identification originally. The species concerned is presumably Mysia ampla, the only use in mollusca of this specific name by Hutton. Where the combination with Miltha came from is hard to say. It has not been suggested in any publication known to the writer. Hutton's original generic placing, Mysia Leach, 1827 = Diplodonta Bronn, 1831 = Taras Risso, 1826, is substantially correct.

Pteromyrtea Finlay, 1926.

Another New Zealand genus discussed by Chavan (1938, p. 231) is Pteromyrtea. This he suggested to be a branch of Cavilucina Fischer, type, the Eocene L. sulcata Lamk, influenced, no doubt, by the obsolescence of the cardinal teeth. Now, there is a widespread tendency in the family to obsolescence of the teeth, so that parallels are very likely to develop, and must be taken into account in classification. Consequently it seems to the writer that a number of very different lineages are combined in Chavan's conception of the “phylum” Cavilucina.

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In its young stages, at least up to 10 mm. diameter, P. dispar, the genotype of Pteromyrtea, has well developed cardinals and laterals and agrees closely in hinge and general shape with the adult of the Miocene P. laminata Hutt. This adult shows no signs of obsolescence of the cardinals, but is undoubtedly an ancestor of dispar. In general appearance, neglecting the obsolete hinge, Cavilucina sulcata shows more resemblance to Gonimyrtea than to Pteromyrtea, which is strongly alate, both anteriorly and posteriorly.

Incidentally, Chavan (1938, p. 88) cites “Loripes” laminatus Hutton as a Myrtea. He was probably misled by specimens in the Cossmann collection, wrongly labelled so, and really the new species described below as M. valdesculpta. Suter confused this common Awamoan shell with Pteromyrtea laminata (Hutt.) which is known to the writer only from White Rock River, Pareora.

Myrtea, Eulopia, Notomyrtea.

There has been a good deal of confusion, for much of which the writer must plead guilty, in the use of Myrtea, Eulopia and Notomyrtea for a number of New Zealand fossils. The type of Myrtea Turton, 1822, is by monotypy the Recent Mediterranean Venus spinifera Montagu; that of Eulopia Dall, 1901, the Recent Lucina sagrnata Dall, from the Gulf of Mexico; and that of Notomyrtea Iredale, 1924, the Recent, New South Wales Myrtea botanica Hedley. Dall separated Eulopia because of the interstitial radials, but Iredale gave no justification for Notomyrtea. Examination of more material since the writer (Marwick, 1928, p. 911) stressed the systematic value of the radials compels him to reverse his opinion and to agree with Cossmann and Chavan that they are often quite variable. Nor has any other criterion been found by which to recognize any distinct lineages within Myrtea, and until such criterion is produced, Myrtea should be used for this very compact and easily identified group. True Myrtea is stated by Chavan to be known first from the Oligocene of the United States, then from the Miocene of Europe. The hinge of the Danian Eulopia microlirata Fin. and Marw. (1937) is unknown, so the generic position is obscure. An undoubted Myrtea, however, M. staminifera Marw. occurs in the Duntroonian (Oligocene) at Chatton and Wharekuri.

Gonimyrtea discus n. sp. Plate 26, fig. 13; plate 27, fig. 26.

Shell like the Recent concinna Hutton but having a less prominent umbo and shallower lunule, also a higher dorsal margin, giving an almost circular outline. The lunular margin of the right valve in concinna is strongly convex, encroaching on the left lunule, but in discus the margin is almost straight. The right anterior lateral tooth of concinna is sometimes very weak, but in discus it is absent altogether. There is a weak right posterior lateral. The irregular internal radial ridges that tend to crenulate the margin of concinna are finer in discus and the margin is smooth.

Height, 6.8 mm.; length, 7 mm.; inflation (1 valve), 1.7 mm. Locality: G.S. 951, Target Gully (Awamoan).

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Pteromyrtea exilis n. sp. Plate 26; figs. 21, 23; plate 27, fig. 27.

Shell small, thin, subcircular, moderately inflated. Anteriorly and posteriorly alate. Lunule deeply excavated, extending across the hinge plate. No escutcheon. Sculpture of fine, regular, concentric lamellae, 6 per mm., with wider interspaces which bear weak radial threads. Lamellae drawn up to crest along posterior dorsal margin, also stronger on anterior area. Right hinge having only posterior cardinal and weak anterior lateral; left hinge having anterior cardinal almost wholly confluent with lunular margin, posterior cardinal present, and extremely weak posterior lateral.

Height, 6.5 mm.; length, 6.5 mm.; inflation (1 valve), 1.5 mm.

Localities: G.S. 2110 (type) and 2222, siltstone Allday Bay; 1160 Awamoa Creek; (Awamoan).

The holotype has weaker sculpture and is more circular in outline than the specimens from other localities. The single right valve from Awamoa Creek (Plate 26; fig. 20) has two well-developed divergent cardinal teeth, and so seems to have developed a left hinge.

Myrtea valdesculpta n. sp. Plate 26; figs. 16, 22; plate 27, fig. 29.

Shell small. sub-triangular, stout. Sculpture of distant, raised lamellae 3 to 4 per mm., the flat interspaces of many specimens bearing wavy radials 8–12 per mm.

Height, 7 mm.; length, 7.8 mm.; inflation (1 valve), 1.6 mm.

Localities: G.S. 951, Target Gully (type); G.S. 1912, Pukeuri; G.S. 2218, Rifle Butts; G.S. 2222, Siltstone, Allday Bay; (Awamoan stage).

This is the common Myrtea of Awamoan horizons, distinguished from the Chatton staminifera (Duntroonian) by the more distant lamellae and more trigonal shape. It was generally mistaken by Suter for Pteromyrtea laminata Hutton, but Finlay (1926, p. 461) long ago pointed out that the two were different. His statement, however, that Suter's figure represents, not laminata, but this hitherto undescribed species cannot be accepted. There seems no reason to doubt the caption to Suter's figures (1915, p. 64), which states that they represent the holotype. A gerontic specimen from G.S. 1160 Awamoa Creek measures 10 mm. × 12 mm.

The radials are not always present.

Cardiliidae.
Genus Cardilona nov.

Genotype: Cardilona bensoni n. sp. Oligocene, N.Z.

Shell of moderate size, cordate, greatly inflated, with beaks prominent, prosogyrous, strongly incurved and distant. Posterior area somewhat winged. Lunule alate, convex, bounded by deep furrow. No escutcheon. Sculpture of rounded radial ridges with narrow interstices. Hinge apparently edentulous, having a strong spoon-shaped chondrophore. Valve margins only slightly crenulated by the ribs.

This peculiar shell is known from but two specimens, both right valves and one of them only an internal cast. It somewhat resembles Cardilia Deshayes, 1835, genotype by original designation, Isocardia

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semisulcata Lamk. from the Moluccas and northern Australia, having a similar oval, inflated shape, well defined posterior area, and spoon-shaped chondrophore. It differs, however, in the absence of hinge plate with cardinal teeth and absence of the posterior lateral flange. It seems probable that the resemblance is only superficial. but no other group can be suggested as a closer relative.

The relations of Cardilia itself appear to be little understood, the systematic position wavering between the Mactridae and the Myidae.

Cardilona bensoni n.gen., n.sp. Plate 25; figs. 4, 5, 6.

Sculpture of about 36 rounded radial ribs, crossed by somewhat irregular growth-lines. The ribs differ considerably in strength, the 1st and 2nd from the lunule being very broad, the 6th and 7th, 13th and 14th, and 22nd to 26th narrow; the 27th and 28th are wide, the latter being rather sunk and bounding posterior wing; the 29th to 36th, on wing, are somewhat flattened and bevelled and become weaker and indefinite dorsally.

The position of the ligament is uncertain.

Height, 38 mm.; length, 30 mm.; inflation (right valve), 20 mm.

Localities: G. S. 2141, green calcareous tuffs, Bridge Point 3 miles south of Kakanui (Kaiatan Stage, Oligocene) holotype; G.S. 626, Isis bed, Campbell's Beach, Allday Bay (? Waitakian Stage, Oligocene), internal cast.

The internal cast is almost smooth, showing neither reflected sculpture nor chondrophore. The shape, the huge lunule and the strongly incurved beaks, however, leave no doubt as to generic identity with bensoni. A low rounded radial ridge on the cast occupies the position of about the 21st rib of bensoni and another radial ridge or step bounds the slightly sunken posterior wing. The muscle scars are not clearly marked, but the anterior one appears to have been fairly long and oval.

The specific name is in honour of Dr. W. N. Benson, who visited Bridge Point with Mr. D. A. Brown and the writer in 1941.

Trochidae.
Genus Levella nov.

Genotype: Levella tersa n. sp. Lower Miocene, N.Z.

Shell very small, thick, conic, smooth, imperforate. Protoconch smooth of about two whorls with fairly large, tilted nucleus which is somewhat immersed. Spire whorls gently convex, body definitely angled at periphery, base gently convex. Surface smooth and shining. Aperture subquadrate; outer lip bevelled and thickened within, inclined back from suture, slightly concave. Columella concave, smooth, merging below anterior margin. Inner lip slightly raised, expanded, but solid. No umbilicus.

This genus is perhaps related to Micrelenchus Finlay, 1926, type Trochus (Gibbium) sanguineus Gray, but it differs in the tilted nucleus, absence of spiral sculpture and in the sharply defined, solid, raised outer margin of the inner lip. It somewhat resembles Boutillieria montensis (Br. and Corn.), but probably only superficially,

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Figs. 1, 2.—Chlamys venosa (Hutt.). Holotype × 1.4; plesiotype, Bridge Point, × 1.2.
Fig. 3.—Janupecten subteres n.sp. Left valve, 1821 Wharekuri, × ·75.
Figs. 4—6.—Cardilona bensoni n.gen., n.sp. Holotype × 1.25.
Fig. 7.—Janupecten subtcies n.sp. Holotype × ·8.

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Fig. 8.—Macrozafra formosa n.sp. Holotype × 7.5.
Fig. 9.—Goniscala di [ unclear: ] nina n.gen., n.sp. Holotype × 7.
Fig 10.—Thungia infulata n.sp. Holotype × 10.
Figs. 11. 12—Plesioti [ unclear: ] tton (Turchua) dubius (Marshall) n. sgen. Holotype × 1.5.
Fig. 13.—Gonimgrtea discus n.sp. Holotype × 6.
Fig. 14.—Gegania (Tubena) viola n.sgen., n.sp. Holotype × 12.
Fig. 15.—Levella tersa n.gen., n.sp. Holotype × 20.
Figs. 16, 22.—Myrtea valdesculpta n.sp. Paratype and holotype × 6.
Figs. 17–19.—Pyrgiscilla festiva n.sp Holotype × 16.
Fig. 20.—Pteromyrtea exilis n.sp. Awamoa right valve with left hinge × 6.
Figs. 21, 23.—Pteromyrtea exilis n.sp. Paratype and holotype × 6.
Figs. 24, 25.—Tipua tricineta (Marshall) n.gen. Holotype × 7.

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Fig. 26.—Gonimyrtea discus n.sp. Holotype × 6.
Fig. 27.—Pteromurtea exilis n.sp. Holotype × 6.
Fig. 28.—Waikura davidt n.sp. Holotype × 10.
Fig. 29.—Myrtea valdesculpta n.sp. Holotype × 6.
Fig. 30.—Gegania (Tubena) viola n.sgen., n.sp. Holotype × 5.
Fig. 31.—Levella tersa n.gen., n.sp. Holotype × 10.
Fig. 32.—Pyrgiscilla festiva n.sp. Holotype × 8.
Fig. 33.—Clathrus mackayi n.sp. Holotype × 1.7.
Fig. 34.—Mauidrillia brou [ unclear: ] oni n.sp. Holotype × 7.

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as the type and other European species of Boutillieria show little resemblance.

Levella tersa n. gen., n. sp. Plate 26, fig. 15; plate 27, fig. 31.

Height, 3·2 mm.; diameter, 2·3 mm.

Locality: G.S. 2222, Siltstone Allday Bay (Awamoan).

Liothdae.
Genus Tipua, nov.

(From the Maori Tipua, a goblin).

Genotype: Submargarita trinoinota, Marshall. Bortonian (Mid Eocene).

Shell small, fairly solid, depressed turbinate, pearly within. Sculpture of spiral threads, three of which, on the body whorl, are stronger and form weak angulations. Penultimate whorl angled just above lower suture by uppermost of these stronger threads. Suture descending rapidly when near aperture. Outer lip inclined backwards about 30° from vertical, strongly antecurrent to suture; bevelled within. Inner lip well spread over parietal wall, restricted opposite umbilicus, but expanded below to form narrow funicular ridge entering umbilicus, the expansion broadly grooved parallel to margin.

As suspected by Marshall, the expanded inner lip and funicular ridge entering the very narrow umbilicus show that this shell is not a Submargarita, the monotype of which is S. margarita Strebel (1920, Schwed Sudpol.—Exped., Bd. 6, Zool. 2, lief 1, pl. 5, fig. 71). It is more nearly akin to Cirsochilus Cossmann, 1888, type Delphinula striata Lamk. from the Paris Basin Eocene, differing mainly in the lack of a border to the outer lip, in the smaller umbilicus and in the spreading of the parietal callus. Under Cirsochilus, Cossmann (1918, p. 135) included a great variety of species from Upper Jurassic to Recent, probably representing many widely-separated lines. One of the Recent species, the West Australian Collonia roseopunctata Angas was synonymised with the earlier Monilea, rosea Ten.-Woods by Hedley (1916, p. 34) and put in the genus Charisma Hedley, 1915, type C. compacta Hedley. This group certainly has some resemblance to Tipua, but the wide umbilicus, bounded by a ridge and a faint funicle, give the aperture a very different appearance.

Tipua tricincta (Marshall). Plate 26, figs. 24, 25.

1919. Submargarita? tricinota Marsh., Trans. N.Z. Inst., vol. 51, p. 227, pl. 15, fig. 14.

Ihungia infulata n. sp. Plate 26, fig. 10.

Of the species described I. infulata is nearest to I. luteophila Marw., but it has much weaker axials, which also are slightly more numerous, numbering 11 to 12 per whorl. Each axial bears a small bead just below the suture which thus has a well-marked moniliform subsutural border. The angle of the body whorl is much lower, giving it a flat sided appearance, and on the last half whorl the sculpture inclines to obsolesce. The two basal spirals are weaker than in luteophila.

Height, 3 mm.; diameter, 1·5 mm.

Locality: G.S. 2222, Silstone, Allday Bay (Awamoan).

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Genus Gegania Jeffreys.

1884. Proc. Zool. Soc., p. 365.
Genotype: Gegania pinguis Jeff. op. cit. pl. 27, figs. 10, 10a. Recent, off Portugal.

Gegania has been generally submerged in Tuba Lea, 1933. Both Sherborn and Neave give this name as preoccupied in Vermes by Renier, 1804, and by Fabricius, 1823, in Mollusca. Sherborn stated, however, that Fabricius did not define his genus and that it was accompanied only by 5 specific names, all nomina nuda. Consequently Tuba Fabricius is invalid as itself a nomen nudum, Tuba Renier still remains, and Lea's generic name cannot be used unless Renier can be disposed of. There is an available name for the group in Gegania Jeffreys. Concerning this, Dall (1892, p. 319) wrote “Gegania is an absolute synonym of Tuba; both have a sinistral nucleus, which is, however, so far immersed, or of such small coil, as to appear to a casual examination merely gibbous and dextral. I have verified this fact by most careful study of the typical specimens of Lea and Jeffreys.”

Mathilda prima Laws, 1935, from the Hampden Bortonian, can be classed under Gegania. It has not the high spire of Mathilda and its protoconch is not known. Mathilda kaiparaensis Laws., 1941, appears to belong to Opimilda Iredale, 1929, type M. decorata Hedley.

Subgenus TUbena nov.

Genotype: Gegania (Tubena) viola n. sp. Awamoan, Lower Miocene, N.Z.

Shell conic, umbilicate, thin. Protoconch paucispiral, smooth, tilted about 30° from horizontal and with an immersed nucleus; plainly defined by its sinused aperture from short neanic stage which is slightly swollen, develops two keels, and is itself clearly defined from juvenile axially sculptured stage. Spire whorls with two chief keels, a third weaker one soon developing above, and a fourth, still weaker, below. Fine axials which nodulate spirals extend from suture to suture but do not cross base. Umbilicus open, of moderate size, bordered by two cords. Aperture effuse, projecting anteriorly; inner lip gently reflexed.

Tubena differs from Gegania pinguis, also from Tuba striata Lea, in being umbilicate, and in having better developed axial sculpture. The sculpture, indeed, resembles that of Mathildona Iredale, 1929, type M. euglypta Ired. but this shell, besides being imperforate, has a more deviated protoconch and also the shape of Mathilda. Jeffreys did not give an enlarged figure of the protoconch of Gegania and the apex of the shell as portrayed is not unlike that of Tubena; but he described it as “globular and intorted,” again as “bulbous, introverted,” terms that do not well suit Tubena. Cossmann (1895, p. 17, fig. 27) has figured the protoconch of Tuba striata Lea, and this is still more unlike.

Gegania (Tubena) viola n.sp. Plate 26, fig. 14; plate 27, fig. 30.

Shell of moderate size, spire one and a half times height of aperture. Protoconch of little more than one, almost planorbid, tilted whorl, not increasing much in diameter from a fairly large, immersed nucleus. Sculpture: Spire whorls sub-convex, with two distant primary spiral cords, the lower somewhat stronger. The wide inter-

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spaces have each a secondary thread of intermediate strength, and on each side of these, the body whorl has a fine tertiary threadlet. The suture follows a third, somewhat weak, primary cord, and on the base another cord is separated from this by a secondary thread; between these and the umbilical margin, five sub-equal threads. Two cords, with a threadlet between, bound the umbilicus and another threadlet lies just within it. Aperture subcircular, with effuse margins, unfortunately for the greater part broken. Outer lip gently and broadly sinused.

Height, 12 mm.; diameter, 8 mm.

Locality, G.S. 2110, upper part of siltstone, Allday Bay (Awamoan).

Genus PLesiotriton Fischer.

1884. Manuel Conch., p. 654.
Genotype (by original designation): Cancellaria volutella Lamk. Eocene,
Paris Basin, Figured. Cossmann, Ess. 5, pl. 4, figs. 6. 7.

Subgenus TUrehua nov.

(From the Maori, Turehua = dimly seen).

Genotype: Latirus dubius Marshall. Bortonian (Eocene) N.Z.

Shell of moderate size, narrowly fusiform. Sculpture of curved, strong axial ribs, somewhat irregular in length, and crossed by distant spiral cords, the interspaces of which bear close, undulating, fine spiral threads. Outer lip varixed, denticulate within. Columella with two median, oblique, parallel plaits, strong internally, but scarcely seen from directly in front of aperture, a third, very weak, spiral plait borders canal. Inner lip thin on parietal wall, but below this, projecting as wide flange free of base and canal, making shallow false umbilicus with bourrelet.

The New Zealand shell is undoubtedly close to Plesiotriton, but its lack of well defined regular varices on the whorls demands more than specific separation. Indeed, these “pseudo” varices are so weak and irregular that they quite escaped the notice of both Suter and Marshall. The columellar folds do not extend nearly so far forward in Turehua as in Plesiotriton s. str.

Plesiotriton (Turehua) dubius (Marshall). Plate 26, fig. 12.

1919. Latirus dubius Marsh., Trans. N.Z. Inst., vol. 51, p. 229, pl. 16, fig. 8.

1924. Latirus (?) marshalli Finlay, P. Mal. Soc. 16 (2), p. 102.

The specific name dubius was changed to marshalli by Finlay because of Suter's note (1908, p. 369) that the name was “preoccupied in Latirus by Beyrich.” This is not, however, a clash between absolute homonyms for Cossmann (1901, p. 43) cited the Oligocene fossil he was placing under Latirus as being “Turbinella dubia Beyr., after the Monograph of M. von Koenen.” While both shells were classed under Latirus, Marshall's dubia, being the later, could not be used, but removal of the New Zealand species to Plesiotriton necessitates the revival of dubia in place of marshalli.

The writer has not been able to see Beyrich's original publication, nor von Koenen's monograph, but the Turbinella dubia Defrance, Dict. Sci. Nat. 1828, listed by Sherborn, probably invalidates T. dubia Beyrich.

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Genus CLathbus Oken.

1815. Lehrb. Nat., pt. 3, No. 1, p. 255.
Type (by tautonymy) Turbo clatthrus L. (= communis Lamk. = spurius Oken).
Recent, Europe.

This is the first record of Clathrus from New Zealand. It is easily distinguished from Epitonium by the absence of a basal disc.

Clathrus mackayi n. sp. Plate 27, fig. 33.

Shell very large, solid, imperforate, no basal disc. Holotype of 4 ½ whorls, the body with 20 and earlier whorls with 19, 17, and 16 ribs. These ribs differ considerably in thickness, and each whorl bears two, some three, considerably thicker, variciform ribs, irregularly placed. (Four fragmentary paratypes show much greater extremes in rib-thickness, but the arrangement and number of thick ones is quite irregular.) Ribs recurved, with finely laminate edges, nearly all curving back from suture against corresponding rib on previous whorl, and drawn up to a pointed crest to form broad subsutural channel. Interspaces with very fine, somewhat irregular, vertical striae, crossed by extremely fine spiral grooves super-imposed on faint indications of spiral threads which are irregularly, developed but of the order of 20 per whorl. Aperture strongly effuse below, producing a broad, strongly marked, raised fasciole.

Height (incomplete), 58 mm.; diameter (incomplete), 32 mm.

Localities: G.S. 626 (type), G.S. 1211, Isis bed, Campbell's Beach, Allday Bay, North Otago (Waitakian Stage, Upper Oligocene).

This species is named in honour of its collector, New Zealand's greatest field geologist, Alexander McKay.

Genus GOniscala nov.

Genotype: Goniscala diurna n. sp. L. Miocene, N.Z.

Shell small, turriculate, imperforate. Protoconch, styliform, of about 5 whorls bearing very faint, sigmoid axial ribs, about 20 per whorl. Whorls angled, high on early whorls, but on later ones near middle. Basal disc present. Sculpture of spaced, uniformly strong, smoothly rounded, axial ribs, crossed by distant spiral cords. Base with spirals but no axials. Basal bourrelet, scarcely, if at all, developed.

Of the subdivisions presented by Cossmann, Goniscala has most in common with Punctiscala, at all events with the species foresti de Boury (Cossm. 1912, pl. 4, figs. 3, 4). This, however, is not the genotype. Both foresti and diurna have a styliform protoeonch, angulate whorls, uniform axials without varices and a basal disc without axials. Punctiscala of course, is characterized by spiral punctae, but since these are altogether absent from the New Zealand fossil, that genus is unsatisfactory. Other groups classed near Punctiscala, but without punctae, such as Funiscala and Torquatiscala are of a different shape.

Goniscala diurna n.sp. Plate 26, fig. 9.

Protoconch with whorls gently convex, increasing very slowly, considerably narrower than the first neanie whorl. Sculpture of 12 axials per whorl, corresponding on each, but with about one-quarter whorl twist for the whole 12 whorls Spire whorls with three distant

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spiral cords, the highest following the angle, all rather weaker across the axials. Base with three spaced spirals.

Height, 8·6 mm.; diameter, 2 mm.

Locality, G.S. 2222. Siltstone, Allday Bay (Awamoan).

Cirsotrema angulata Marw. is superficially similar, but it has the basal axials and bourrelet of Cirsotrema.

Pyrgiscilla festiva n.sp. Plate 26, figs. 17, 18, 19; plate 27, fig. 32.

Shell of relatively moderate size. Protoconch paucispiral bulbous, with large nucleus, partly immersed by the first axial ribs which ascend on the nucleus considerably higher than does the last part of protoconch. Whorls at first cylindrical, turretted, later less impacted and having slightly concave sides; base rather quickly contracted. Sculpture of about 15 strong axials per whorl with somewhat wider interspaces abruptly limited just above suture line; interspaces and base bearing rather weak spirals.

Height, 6·8 mm.; diameter, 1·8 mm.

Locality: G.S. 2222. Siltstone, Allday Bay (Awamoan).

This species is probably on the line of P. chattonensis (Marw.), but is distinguished by its higher, slightly concave and more staged whorls, and the less rounded periphery.

Waikura davidi n.sp. Plate 27, fig. 28.

Protoconch with about one whorl exposed, having rather globose, immersed nucleus tilted at about 30°. Sculpture of strong, rounded ribs, curving forward to suture above and extending equally strongly to lower suture, but dying out just below basal periphery.

Height, 3·5 mm.; diameter, 1·5 mm.

Locality: G.S. 2222, Siltstone, Allday Bay (Awamoan).

W. davidi differs from the other species of Waikura except hawera Laws in having the ribs persist strongly to the lower suture. From hawera the new species is easily distinguished by the different shape and by the bending forward of the ribs to form a subsutural border.

Macrozafra formosa n.sp. Plate 26, fig. 8.

Shell small, broadly subulate fusiform; spire whorls flattened, to slightly concave, but bulging above suture. Body flattened above sub-angled periphery, base contracting rapidly to short, straight neck. Protoconch damaged but as far as can be seen like M. subabnormis. Sculpture of about 13 axial ribs per whorl; these extend from suture to suture, and each is drawn up to low, rounded tubercle at periphery, which is very low on whorl. Ribs low, rounded, and separated by somewhat wider concave interspaces. Only faint suggestions of spirals present on spire whorls and body, but neck bearing about 7 rounded spirals with linear interstices. Columella straight above, bending gradually to canal without a fold.

Height, 6 mm.; diameter, 2·5 mm.

Locality: G.S. 2222. Siltstone, Allday Bay (Awamoan).

This shell is not a strict Macrozafra, but it can remain with that group until more is known of its affinities.

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Volutidae.
Genus Mauira nom. nov.

Genotype: Galeodes maoriana Suter. Bortonian

The generic name Mauia Marwick, 1926 (p. 271) is preoccupied by Blackburn, 1885 (p. 194) in Coleoptera. Consequently the name Mauira is proposed as a substitute.

Mauidrillia browni n.sp. Plate 27, fig. 34.

Shell small, fusiform. Protoconch smooth, paucispiral, globose, of about 1 ½ whorls with large nucleus. Whorls angled about middle, with concave shoulder and periphery wider than lower suture on later whorls; base contracted at first slowly then quickly to fairly long neck. Sculpture at first of 10, later increasing to 12 or more strong axials extending from suture to suture but not down base; these are drawn to strong tubercles on shoulder angle and to small tubercles just below suture. Whole surface with weak, close, spiral cords, more plainly marked on base, about 5 on shoulder and 20 on body, those on neck finer, Apertural sinus broad, strongly defined by growth lines. Anterior canal without notch. Columella with a gentle twist that produces a prominent bourrelet on the neck.

Height, 7 mm.; diameter, 3 mm.

Localities: G.S. 2110 (type), G.S. 2222. Siltstone, Allday Bay (Awamoan).

This species is closely related to unilirata Powell, but it differs in having fewer and stronger tubercles, and a rather longer twisted neck.

This species is named in honour of Sub-Lieut. David A. Brown.

References.

Blackburn, 1885. Trans. Roy. Soc. Dublin (n.s.), vol. 3.

Chavan, A, 1937. Essai critique d. class d. Lucines, pts 1, 2, 3. Journ. d. Conch., vol. 81.

Chavan, A. 1938. Essai crit. d. class d. Lucines, pts. 4, 5, 6. Journ. d. conch., vol. 82.

Cossmann, M., 1895. Ess. Paléoconch Comp., livr 1. Paris.

—, 1901. Ess Pal. Comp., livr. 4.

—, 1903. Ess. Pal. Comp., livr. 5.

—, 1912. Ess. Pal. Comp. livr. 9.

—, 1918. Ess. Pal. Comp., livr. 11.

Dall, W. H. 1892. Tert. Moll. Florida, Trans. Wag. Free Inst., vol. 3, pt. 2.

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

Hedley, C., 1916. Moll. West Australia. Journ. Roy. Soc. West. Aust., vol. 1.

Park, J., 1918. Geol. Oamaru Hist. N.Z. Geol. Surv. Bull., No. 20 (n.e.).

Suter, H. 1908. Descript. New Species N.Z. Moll. Trans. N.Z. Inst., vol. 40.

— 1915. Revision of Tert. Moll. N.Z. Geol. Surv. Pal. Bull., No. 3.