b. Subgenus Austrodosinia Dall, 1902.

Type: Cytherea anus Philippi.

Austrodosinia has coarse concentric ridges which rise into a crest bounding the escutcheon and are also well raised near the lunule. The hinge has rugose, somewhat narrow but long median cardinals in both valves. These are slightly bevelled and grooved along their whole length. The left anterior lateral is extremely large and very rough, as is also the pit for its reception. The pallial sinus is horizontal, and rather short.

Jukes-Browne thought that in D. anus “the middle cardinal teeth are not bifid in adult shells being merely rugose, in young shells the left middle cardinal is grooved near the top, but that of the right is not bifid.” Fig. 12 below gives a dorsal view of a large Recent specimen 73 mm. long, and clearly shows that he was mistaken.

In Dosinia s. str., Phacosoma, etc., the median cardinals are more triangular, more strongly bevelled and the grooves divide the teeth more unequally.

c. Subgenus Phacosoma Jukes-Browne, 1912.

Type: Artemis japonica Reeve.

Jukes-Browne severely criticised Dall's Dosinorbis, type D. bilunata (Gray), saying that the feature on which the genus was founded, i.e., the appearance of a double lunule, was a specific not a generic character. He therefore chose what he considered a more typical species D. japonica as type of a new genus Phacosoma to which he referred Dall's Dosinorbis. This mistake in method was pointed out by Iredale (1915, p. 494) who, considering the matter mainly from the standpoint of the literature, revived Dosinorbis and placed therein D. subrosea and D. caerulea, though it is not clear whether he meant the true D. caerulea or Suter's wrong interpretation of it (now D. maoriana Oliver).

The writer favours Dall's isolation of D. bilunata under Dosinor-bis as a monotypical subgenus and the recognition of Phacosoma, because the peculiar anterior area in D. bilunata, like a second larger lunule, has probably quite a long history behind it, and the disposition of the anterior cardinals and laterals is different from that of Phacosoma. No specimen of D. japonica was available for the present revision, so the writer has had to base his conception of Phacosoma on a fossil specimen of D. troscheli Lischke, and on figures and descriptions of the type. If this species is correctly associated with D. japonica there is little difference between Phacosoma and Dosinia s. str. except in the escutcheon which is deeper in Phacosoma; the shape of the shell and the arrangement of the hinge-teeth are practically the same.

d. Subgenus Raina n. subgen. (from Ra the Maori Sun God).

Type: Dosinia bensoni Marwick.

Shell large. Lunule long, only slightly impressed, well defined; escutcheon broad and deep in left valve, smaller in right. Sculpture of light concentric grooves separating flat polished interspaces which are raised into low narrow ridges near lunule and on posterior area. Left hinge with high curved posterior cardinal; rather narrow, straight median cardinal unequally divided; and long straight anterior cardinal; anterior lateral strong, elongate, rugose on lower side. Right hinge with long, broad, deeply and widely grooved, posterior cardinal with shoulder at top; a somewhat narrow, rugose grooved median cardinal; and a very weak anterior one; lateral pit large but shallow, rugose on lower side, almost smooth above. Pallial sinus short, angular, ascending.

Raina is characterized by its large, shallow lunule, very large shouldered right posterior cardinal, and short, angular, ascending sinus. The Mid-Tertiary type species has a polished surface with light concentric grooves separating flat interspaces, but on Pliocene descendants the sculpture is stronger so that the interspaces become raised ridges and the surface is like that of Austrodosinia.

e. Subgenus Kereia, n. subgen. (from Kawana Kerei—the Maori name for Governor Sir George Grey.

Type: Dosinia greyi Zittel.

Shell inflated. Lunule shallow, bounded by deeply incised line; escutcheon absent. Sculpture of distant, raised, sharp, concentric lamellae. Teeth strongly divergent; right hinge with a short lamellar anterior cardinal; triangular grooved median, and very broad, grooved, posterior cardinal; anterior pit long, rugose on lower side with well defined lateral above, weaker one below. Left hinge with long triangular anterior cardinal; broad, grooved, median; and high lamellar posterior cardinal; anterior lateral long, only moderately high, rugose.

This subgenus is easily distinguished by its high, spaced lamellae and divergent teeth. In the early Tertiary species D. mackayi and D. ongleyi the concentric lamellae have not yet developed.

f. Subgenus Kakahuia n. subgen.

Type: Dosinia suteri, Marwick.

Shell rather small, roundly trigonal, beaks high. Lunule shallow, bounded by an incised line; escutcheon narrow in right valve, probably wider in left. Sculpture of fine spaced concentric lamellae, two to three per mm. Hinge of right valve with broad curved grooved posterior cardinal; rather narrow entire median cardinal, paired with moderately strong entire anterior one, both sloping forward; anterior pit deep, rugose below and with weak lateral above. Nymph deep, striated on ligamental and resiliary surfaces.

Dosinia (Dosinia) lambata (Gould) 1850 (Figs. 8, 9, 11).

For synonymy see Suter's Manual, p. 976.

Localities.—Recent (type);

Castlecliff, Wanganui;

Maraekakaho, Ngaruroro River;

876, Mouth of Waihi Stream, Hawera;

858, Starborough Creek, Marlborough;

Trig. Z., Otekaike, Waitaki Valley.

Easily distinguished by its prominent beaks, shallow escutcheon, and extremely fine sculpture.

Dosinia (Austrodosinia) anus (Philippi) 1848 (Figs. 7, 10, 12, 13).

For synonymy see Suter's Manual, p. 978.

Localities.—Recent (type);

Shrimpton's, Ngaruroro River (H. J. Finlay coll.);

Nukumaru.

Dosinia (Austrodosinia) magna Hutton (Figs. 18, 19).

1873. Dosinia magna Hutton, Cat. Tert. Moll., p. 22.

1914. Dosinia magna Hutton: Suter, N.Z. Geol. Surv. Pal. Bull. No. 2, p. 50, pl. 14, fig. 7.

Practically every large Dosinia from the Oamaruian has been identified as D. magna, but an inspection of the hinge and other characters shows that there are several undescribed species, particularly from Awamoan horizons. Figure 18 shows the hinge of the holotype, a left valve, while the right valve, fig. 19, was collected by Dr. J. A. Thomson from the shell bed at the base of the Pareora Beds, junction of Porter and Thomas Rivers, Trelissick Basin, and

so may be a topotype. The left valve has an enormous, bluntly-conical, anterior lateral tooth, a lamellar anterior cardinal, a very broad, unequally-divided, median cardinal, and an arched posterior cardinal which, with the raised lunular margin, forms a semicircle.

In the right valve the posterior cardinal is only of moderate width, the median cardinal has a semilunar shape and appears to be entire. The anterior pit is deeply excavated and has low rugose laterals. The lunule is fairly broad and rather well impressed, but the margin is arched and pouts strongly. The pallial sinus though obscured, appears to be of only moderate depth and to point about the bottom of the anterior adductor. The true sculpture was in no case seen; but the specimen collected by Dr. Thomson seems to have had close, raised, concentric ridges.

Localities: Trelissick Basin (type); Ardgowan, Oamaru (H. J. Finlay) fragment; 8B Clifden, Southland (H. J. Finlay).

Dosinia (Austrodosinia) kaawaensis n. sp. (Figs. 14, 15).

Shell of moderate size, suborbicular, thin, flat; beaks fairly prominent. Lunule very small, deeply impressed, narrowly lanceolate; escutcheon narrow in right valve, stronger in the left. Sculpture of fine, erect, sharp, spaced, concentric ridges which narrow, towards the extremities and form a crest to the escutcheon. Hinge plate narrow and somewhat weak; right valve with an almost vertical, lamellar anterior cardinal; median and posterior cardinals of about equal strength and bifid; anterior pit with low corrugated laterals. Left valve with thin posterior cardinal; median strong, unequally divided; anterior vertical, lightly arched; anterior lateral elongated, rugose. Pallial sinus linguiform, horizontal.

Holotype in the collection of N.Z. Geol. Survey.

Height 40 mm., length 43 mm., thickness (1 valve) 8 mm.

Localities: 996, Kaawa Creek (= D. anus of Bartrum, 1919, p. 104); 1171, Patea.

Remarks: This shell is closely related to D. anus the chief difference being in the erect posture of the concentric ridges which in D. anus are broadly bevelled and relatively low.

Dosinia (Austrodosinia) waitakiensis n. sp. (Figs. 20, 22).

Shell large, solid, lunule moderately impressed, escutcheon deep; sculpture of strong, raised, concentric ridges with polished bevelled edges, becoming more erect and narrower distally, teeth like those of D. magna except that the anterior lateral is long, somewhat narrow and extremely rugose.

Type in the collection of Mr. H. J. Finlay.

Estimated diameter 60 mm.

Locality: Otiake, Waitaki Valley.

Dosinia (Austrodosinia) horrida n. sp. (Figs. 35, 38, 41).

Shell fairly large, circular, compressed. Lunule lanceolate, small, deeply impressed; escutcheon narrow in right valve, traversed by concentric ribs, in left valve fairly broad, well defined, smooth. Sculpture of strong, high, well-spaced ridges which become narrower and higher distally forming a crest to the escutcheon. Right hinge with small anterior cardinal; moderate, grooved median; and stronger,

curved, grooved posterior cardinal; nymph margin raised into lamella; anterior lateral pit deep, upper lateral well defined, lower side of pit strongly rugose. Left valve with curved lamellar posterior cardinal, moderate, unequally-grooved median; and curved, grooved anterior cardinal also of moderate strength but slightly longer; anterior lateral long, strong, deeply rugose. Pallial sinus broad, linguiform, horizontal, reaching about half-way across shell.

Holotype in collection of N.Z. Geological Survey.

Height 51 mm., length 47 mm., thickness (one valve) 12 mm.

Localities: 1164, Nukumaru Beach (type); 1102, Maraekakaho Creek.

The sculpture resembles that of D. waitakiensis, but is finer, the lunule is smaller and deeper and the anterior tooth of the left valve is curved backwards and so remains close to the median.

Dosinia (Phacosoma) subrosea (Gray) 1835. (Figs. 25, 26, 28).

For synonymy see Suter's Manual, p. 979.

Localities: Recent (type); Nukumaru?

Only incomplete examples of the Nukumaru shell have been seen, but apparently it has a shallower escutcheon, and the cardinals are somewhat more divergent than in the Recent shell. Further material is required before any reliable distinction can be made. A still older ancestor of D. subrosea occurs in the Waipipi beds, the hinge, however, is as yet unknown.

Dosinia (Phacosoma) wanganuiensis n. sp. (Figs. 24, 29, 30).

Shell large, strong. Lunule deeply impressed; escutcheon narrow, especially in right valve. Sculpture of bevelled, close, concentric ridges, 12 to 15 per centimetre. Hinge of left valve with long, thin, posterior cardinal; long, moderately thick, bevelled median cardinal with groove marking off low short anterior flange; and lamellar anterior cardinal; anterior lateral fairly strong, broad, somewhat rugose. Right valve with long, narrow, grooved posterior cardinal; broadly-triangular bevelled median cardinal with slight shoulder on posterior side; and short entire anterior cardinal; anterior lateral pit deep, broad, rugose with raised margins. Pallial sinus fairly deep tapering to narrow end, directed at middle of anterior adductor.

Holotype in collection of N.Z. Geological Survey.

Height 60 mm., length 63 mm., thickness (one valve) 15 mm.

Locality: Castlecliff, Wanganui.

Easily distinguished from D. subrosea by larger size and much coarser sculpture, the ridges being 12 to 15 per cm. instead of 20–25.

Dosinia (Phacosoma) maoriana Oliver (Figs. 4, 5, 6).

1906 Dosinia caerulea Reeve: Suter, Trans. N.Z. Inst., vol. 38, p. 318 (not of Reeve).

1913 Dosinia caerulea Reeve: Suter, Manual N.Z. Moll., p. 977, pl. 60, fig. 8.

1923 Dosinia maoriana Oliver, Proc. Malac. Soc., vol. 15, p. 188.

This species is distinguished by its constant orbicular shape, insignificant escutcheon, and long rather narrow pallial sinus, rounded at the apex and pointing about the middle or upper part of the

anterior adductor. The anterior lateral tooth is tubercular and not so strong as that of D. subrosea.

Localities: Recent (type): Castlecliff, Wanganui.

Dimensions: Generally about 30 mm. high, but fossil specimens are as much as 52 mm.

Dosinia (Raina) bensoni n. sp. (Figs. 34, 36, 54).

Shell large, solid, suborbicular. Dorsal margin arched. Lunule long, lanceolate, moderately impressed; escutcheon fairly deep, well marked in left valve, much less so in right. Sculpture on central half of disc of narrow concentric grooves separating broad flat polished interspaces up to 2 mm. in width; on anterior and posterior these interspaces are raised into narrow ridges. Hinge-plate broad, arched; left valve with posterior cardinal strong and curved; median of moderate strength, unequally divided; anterior cardinal fairly strong, lateral tooth elongate, rugose, strong. Right valve with anterior cardinal short, high and thin; median strong, rugose, unequally divided; posterior strong, gently arched, deeply grooved, bearing a small projecting plate on left side of upper end; edge of nymph raised into sharp lamella; anterior lateral pit well defined, rugose on lower side. Pallial sinus relatively short, acute, pointing at top of anterior adductor.

Holotype: deposited in collection of N.Z. Geological Survey by Dr. P. Marshall.

Height 70 mm., length 72 mm., thickness (one valve) 19 mm.

Localities: Target Gully (type): Ardgowan; Awamoa; 1130, Mokau beds, Mohakatino River; 1150, Mokau beds, junction Papakino and Tongaporutu Rivers; 1209, Quarry on Dannevirke-Herbertville Road, two miles N.W. of Waipatiki oil bore.

The true sculpture is often removed by weathering and the surface is then marked by spaced concentric ridges with smooth or striated interspaces. These shells can be distinguished from D. magna with which they have been previously confused, by the narrower left median cardinal, smaller, compressed anterior lateral, rugose divided right median cardinal and narrow superficial lunule.

Dosinia (Raina) paparoaensis n. sp. (Figs. 63, 64, 65).

Shell large, circular, moderately inflated; beaks low, at anterior fourth; dorsal margin arched, high. Lunule shallow, narrowly lanceolate; escutcheon insignificant. Sculpture probably of close strong concentric ridges, but owing to weathering this feature is not clear, weathered surface generally marked by strong concentric ridges sometimes regularly spaced. Left valve with thick grooved median cardinal, and narrow posterior and anterior ones; anterior lateral rather large, low, elongate, conical, rugose. Right valve with thick grooved posterior cardinal; moderate, grooved median; and small but strong anterior one; lateral pit well marked, rugose. Pallial sinus deep, pointing to the top of the anterior adductor.

Type in the collection of the N.Z. Geological Survey.

Height 53 mm., length 55m., thickness (one valve) 13 mm.

Locality: Paparoa Rapids, Wanganui River.

Remarks: This species resembles D. bensoni in its shallow lunule and rough surface when weathered. It can be distinguished, however,

by its small escutcheon, more closely placed left anterior and median cardinals, stronger right anterior cardinal, deeper sinus, high, arched dorsal margin and smaller size. This is the D. subrosea and probably D. anus of Marshall and Murdoch (1921, p. 85).

Dosinia (Raina) waipipiensis n. sp. (Figs. 49, 51).

Shell very large not much inflated. Lunule lanceolate, large, not very deeply impressed except towards anterior end, pouting strongly; escutcheon probably well-developed, but the single fragmentary right valve shows only the beginning of it. Sculpture of strong, sharp, raised, bevelled, spaced concentric ridges becoming lamellar and inclined distally. Hinge of right valve with high lamellar anterior cardinal; strong, slightly curved, weakly-grooved rugose median; and broad, deeply-grooved, curved posterior cardinal bearing on top anterior side a strong projecting shoulder; edge of nymph raised into strong lamella; anterior pit long with long well-defined lateral tooth above forming a continuation of the anterior cardinal, lower side of pit deeply rugose, the rugosities somewhat obscuring the lateral tooth. Pallial sinus reaching about half-way across shell, with narrow point directed at middle of anterior adductor.

Holotype in collection of N.Z. Geological Survey (deposited by Dr. P. Marshall).

Height (estimated) 75 mm., length (estimated) 80 mm., inflation (one valve) 18 mm.

Locality: Waipipi Beach, Waverley.

The strong spaced ridges with concave interspaces easily distinguish this shell from D. bensoni and D. nukumaruensis.

Dosinia (Raina) nukumaruensis n. sp. (Figs, 43, 45, 46).

Shell large, inflated, orbicular. Lunule large, lanceolate, not very deeply impressed, but well defined; escutcheon absent from right valve, well marked but narrow on left. Sculpture of fine, close, bevelled, low, concentric ridges. Hinge of right valve with short narrow anterior cardinal; strong rugose grooved median; and strong curved bifid posterior one bearing a projecting shoulder on anterior upper end; lower edge of nymph with raised lamella almost parallel to posterior cardinal; anterior lateral pit well marked, rugose on lower side. Left valve with fairly strong arched posterior cardinal; moderate, unequally-divided median; and slightly thinner, straight, grooved anterior cardinal; anterior lateral strong, elongate, somewhat rugose. Pallial sinus acute, pointing about middle of anterior adductor, reaching not quite half-way across shell.

Type in collection of N.Z. Geological Survey.

Height 68 mm., length 64 mm., thickness (one valve) 20 mm.

Localities: 1164, blueish sands, Nukumaru Beach; 1173, mouth of Waihi Stream, Hawera.

Easily distinguished from D. bensoni by the raised, bevelled ridges and the slightly deeper escutcheon. The hinges of these two species are practically the same.

Dosinia (Kereia) ongleyi n. sp. (Figs. 37, 39, 58, 59).

Shell small, circular, not inflated. Lunule large, lanceolate, somewhat impressed, pouting, bounded by well-incised line; escutcheon

narrow, bounded by well-defined ridge in left valve but not in right. Sculpture of concentric ridges with somewhat concave interspaces about two per mm. Right hinge with somewhat narrow, grooved posterior cardinal; short triangular, grooved median cardinal front edge sloping forward; fairly long, entire, anterior one also directed well forward; anterior pit part of a groove extending from between two front cardinals. Left hinge with long, narrow, slightly-curved posterior cardinal well separated from nymph by wide groove; moderately strong, bevelled, grooved median cardinal; very long narrow anterior cardinal curving forward below and running along hinge-margin; anterior lateral long and narrow, almost in a line with anterior cardinal. Nymphs hollowed out below the ligamental surface which is very short. Pallial sinus deep, ascending, directed at lunule. Valve margins smooth.

Holotype in collection of N.Z. Geological Survey.

Height 14.5 mm.; length 16 mm.; thickness (one valve) 12 mm.

Locality: Wangaloa (= Dosinia greyi Zittel of Suter 1921, p. 96).

The surface of the type is raised into ridges only on the early part, the later having concentric grooves separating flat interspaces of different widths on the centre of the disc. There are, however, sharp ridges on the posterior area.

Dosinia (? Kereia) perplexa n. sp. (Figs. 40, 53).

This species is based on a single right valve identified by Suter (1921, p. 96) as D. lambata. The sculpture consists of concentric ridges like most specimens of D. ongleyi, and the lunule also is the same. The umbones, however, are further forward and more prominent so that the outline is indeed like that of D. lambata. The right hinge has a broad, grooved posterior cardinal; and a narrowly-triangular, bevelled, grooved median one; but the anterior cardinal appears to be scarcely developed, forming with the upper anterior lateral a low ridge bounding a groove proceeding from between the two front cardinals and forming the anterior lateral pit. The lateral on the lower side of the pit is not joined to the median cardinal.

Holotype in collection of N.Z. Geological Survey.

Height 18 mm.; length 21 mm.; thickness (one valve) 15 mm.

Locality: Wangaloa.

If the hinge as described is normal, this shell should be made the type of a new genus. There is no sign of fracture to show that the anterior cardinal has been broken off, the low ridge being smoothly rounded on top. The lunular margin, however, is thick and invading the hinge-area. It is just possible that it is an abnormal development which caused the atrophy of the anterior cardinal, but this does not seem likely. However, until more light can be shed on the subject, the species is included under Kereia.

Dosinia (Kereia) mackayi n. sp. (Figs. 21, 31, 32, 33).

Shell small, thick, moderately inflated; beaks strong; outline almost circular, dorsal margin arched. Lunule not deeply impressed, of moderate size, limited by an incised line; escutcheon long, narrow. Sculpture of rather fine, close, concentric lamellae. Hinge-plate strong, arcuate, right valve with the anterior cardinal lamellar; median

cardinal triangular, grooved, separated by a wide space from the posterior which is strong, curved, and bifid. Left valve with three strongly-divergent cardinals, median strongest, bevelled and grooved; posterior separated by a groove from nymph; anterior lateral long and narrow, fairly prominent. Posterior muscular impression much larger than anterior; pallial sinus deep and wide, ascending, angled and pointing to about the top of anterior muscular impression.

Holotype in the collection of the N.Z. Geological Survey.

Height 25 mm., length 27 mm., thickness (one valve) 7 mm.

Localities: 176, Black Point (holotype); 164, coal greensands, Kakahu.

Remarks: This is the shell listed by Suter (1921, p. 72) as Dosinia magna from which it can be distinguished by its small size, wide spreading teeth, broad, high, pouting lunule and finer ornamentation.

Superficially this species most resembles D. maoriana, being of about the same size and shape, it may be distinguished by the larger and much less impressed lunule, and the divergent teeth.

Dosinia (Kereia) densicosta n. sp. (Figs. 16, 17).

Shell of moderate size, orbicular, flat; beaks inconspicuous. Lunule small, lanceolate, superficial, pouting; escutcheon absent. Sculpture of erect, high, closely-placed, concentric ridges about 1 mm. wide, with striated interspaces of equal width. Hinge-plate of moderate strength; left valve with the anterior and posterior cardinals laminar; median very strong and bifid; anterior lateral moderate, somewhat rugose; nymph narrow. Pallial sinus long and narrow, pointing at the top of the anterior adductor.

Type in collection of Mr. H. J. Finlay.

Height 40 mm. (circ.), length 40 mm. (circ.), thickness (one valve) 9 mm.

Locality: Target Gully.

Distinguished from decorticated specimens of D. bensoni by its broader lunule and regular closely-placed concentric ridges, the left median cardinal is very stout as in D. magna, but the lunule is less arched and narrower than in that species, also the sculpture is different.

Dosinia (Kereia) cottoni n. sp. (Figs. 42, 47).

Shell large, solid, slightly-winged posteriorly; beaks strong, prominent, about anterior fourth, dorsal margin long, arched, fairly high. Lunule large, sagittate, shallow, pouting slightly in young specimens; escutcheon long and broad, keeled. Sculpture consisting of low, regular, erect, concentric lamellae inclined to become horizontal and overlap on posterior. Hinge-plate obscured, but as far as can be seen, left lateral is strong, weakly rugose on lower side, and well separated from anterior cardinal, left posterior cardinal is curved, fairly strong and has outer side longitudinally grooved. Pallial sinus narrow, deep, pointing to top of anterior muscular impression.

Holotype in the collection of the N.Z. Geological Survey.

Height 42 mm., length 46 mm., thickness (one valve) 11 mm.

Localities: 1037, mouth of Hurupi Creek, N.E. corner, Palliser Bay;? Fox River, West Nelson, a distorted specimen, hitherto