Erato antiqua Marshall.

1919. Erato antiqua Marshall. Trans. N.Z. Inst., vol. 51, p. 227, pl. 15, fig. 7.

Distinctive in the very low spire, which scarcely rises above the curvature of the posterior of the shell. Numerous regularly spaced denticles are present along almost the entire length of the inner lip, a feature not commented on by the author of the species. There are two light folds present at the base of the inner lip, the posterior one the more oblique.

Height, 4.5 mm.; width, 3.5 mm. (holotype).

The type is from Hampden. There is a single topotype in the writer's collection.

Type in Wanganui Museum.

Erato accola n.sp. (Fig. 1).

Shell of moderate size for the genus, not unlike E. antiqua in shape and build; but the inner and outer lips are quite parallel, and the spire slightly more in evidence, though scarcely disturbing the normal curvature of the posterior of the shell. The outer lip is

more finely dentate than that of antiqua, and at the base of the pillar there is but one fold, which is heavy and quite conspicuous. Denticles of inner lip weak, dying out at about half its length from anterior.

Height, 6.0 mm.; width, 4.0 mm.

Locality, greensands, McCullough's Bridge (Tahuian).

Type (unique) in writer's collection.

Separable at sight from the Hampden shell in being larger and in having a single strong ridge at base of inner lip.

Erato vulcania Marwick.

1926. Erato vulcania Marwick. Trans. N.Z. Inst., vol. 56, p. 314, pl. 72, fig. 25.

Two topotypes in the writer's collection agree entirely with Dr Marwick's illustration. In addition to the rudimentary denticles on inner edge of outer lip, referred to by Marwick, there are present on one of the topotypes several very weak denticles along anterior third of inner lip. Vulcania is a more heavily built species than either of the foregoing, with higher spire and suppressed denticles to inner and outer lips.

Height, 4.0 mm.; width, 3.0 mm. (holotype).

Localities—Lorne, near Oamaru (Waiarekan), type; Trig. M, near Oamaru, a single specimen.

Type in collection of New Zealand Geological Survey. Two topotypes in writer's collection.

The Trig. M shell is smaller than those from the type locality, but quite definitely referable to Dr Marwick's species. Recent collecting at this locality has brought to light a number of interesting fossils. For the present it is sufficient to note that a not insignificant number of species previously known only from Lorne have been found to form a strong element in the fauna of the beds at Trig. M, viz., Limatula trulla, Mantellum inconspicuum, Serpulorbis lornensis, Lornia limata, Clavatula humerosa, Uromitra lornense, Spirocolpus tophina, Zeacolpus lornensis, Erato vulcania, all of Marwick. In addition, the writer has Argalista n.sp. from both these localities.

Erato aff. vulcania Marwick.

A single specimen agreeing with E. vulcania in all respects, save that the spire is very much less prominent and a good deal more callused. Further collecting may show this feature not to be constant.

Locality, Trig. M, near Oamaru.

Specimen in writer's collection.

Erato senectus Murdoch.

1924. Erato senectus Murdoch. Trans. N.Z. Inst., vol. 55, p. 160, pl. 10, figs. 5, 6.

The shape of this shell is reminiscent of that of E. neozelanica Suter, but closer inspection shows a number of quite distinct characters. In both species the spire is strongly exsert, but senectus is a much smaller species with differently arranged plications at base of columella; has fewer, less distinct denticles on inner lip which

are well outside aperture and not so near edge of inner lip as are those of neozelanica; and five or six teeth-plications on a raised area along the anterior of the outside of outer lip. Neozelanica has a sunken area on pillar separating the columellar ridges from the first of the denticles of inner lip, a feature not present in senectus.

Height, 4.5 mm.; width, 3.25 mm. (holotype).

Locality, shell-bed, Target Gully, Oamaru (Awamoan).

Type in Wanganui Museum. Two topotypes have since been collected, one by Dr Finlay and the other by the writer.

Erato waitakiensis n.sp. (Fig. 2).

Shell of moderate size for the genus, spire forming a distinct conical elevation on posterior surface of shell; aperture rather sinuous, its borders curving in sympathy one with the other; outer lip heavily thickened, convex; inner lip with three very weak plications at base, above which are a number of weak denticles, present for only about half its length above the plications; furrow well seen extending along entire length of inner lip.

Height, 5.0 mm.; width, 3.5 mm.

Locality, Otiake (Waitakian).

Type (sole specimen) in writer's collection.

The denticles along outer lip are weak, low, widely spaced.

Erato clifdenensis n.sp. (Fig. 3).

General shape and build very close to that of E. waitakiensis n.sp., from which it is separable at a glance on account of its finely, regularly, and sharply dentate outer lip. The basal ridges (four in number) also are finer, and are succeeded behind by a row of small, distinct denticles along entire length of the inner lip. The anterior region of inner lip is straight, that of waitakiensis being broadly excavated.

Height, 5.0 mm.; width, 3.0 mm.

Locality, Clifden, Southland, band 7 (Hutchinsonian).

Type (sole specimen) in writer's collection.

Erato submorosa n.sp. (Fig. 4).

Shell small, spire distinct, posterior end of aperture well arched upwards and outwards; outer lip convex with numerous denticles; inner lip broadly excavated at about middle, five fine, close plications below, and weak denticles along border reaching almost to posterior end.

Height, 3.2 mm.; width, 2.1 mm.

Localities—Pukeuri (type) and Target Gully (Awamoan localities). Clifden, Southland, bands 6A, 6B, 6C; bed A, left side of river, and new road-cutting behind racecourse = band 7 of the beds along the river (Hutchinsonian).

Type in writer's collection.

In all, six specimens were obtained at Clifden, four at Pukeuri, and three at Target Gully. The shells from Clifden agree with those from Oamaru in all respects save that the denticles along the outer lip are rather less heavy and more numerous.