Key to Species.

auriformis: circum-umbilical keel set in from the rounded periphery.

huttoni: circum-umbilical keel forming the periphery.

Micreschara (Macromphalina) auriformis n. sp. (Plate 60, figs. 5, 6.)

Shell small, auriform, depressed; spire very low; whorls 3 or 4 rapidly increasing; surface smooth; suture plain, tangential at first, but abutting near aperture; which is oval, distended, and much inclined; outer lip convex, retracted to suture; inner lip concave, straightened below, slightly reflexed; umbilicus very wide, joining base of body-whorl at sharp angle some distance in from rounded periphery.

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

Height, 3.5 mm.; diameter, 5 mm.

Locality.—Boulder Hill (Palaeocene).

Micreschara (Macromphalina) huttoni n. mut. (Plate 60, figs. 1, 2, 3.)

1877. Sigaretus carinatus Hutton, Trans. N.Z. Inst., vol. 9, p. 597 (not of Muenster nor Goldfuss).

1914. Ampullina carinata (Hutton): Suter, N.Z. Geol. Surv. Pal. Bull. 2, p. 10, pl. 8, figs. 2 a, b, c.

1918. Sinum carinatum (Hutton): Suter, N.Z. Geol. Surv. Pal. Bull. 5, p. 88.

Localities.—White Rock River, Pareora (type); Target Gully, Oamaru: (fide P. Marshall). (Lower Miocene or Upper Oligocene.)

M. problematica Desh. and M. decussata Cossm. from the Eocene of the Paris Basin are closely similar to the New Zealand species.

The combination Sigaretus carinatus was preoccupied when Hutton proposed it—by A. Goldfuss, 1837 (Abbild. u. Beschr. d. Petrefakten Deutchlands, &c., iii, 13, t. 168, f. 16), and by Muenster, 1842 (Beitrage zur Petrefakten-Kunde, iv, 93, t. 9, f. 16): therefore the specific name huttoni is proposed.