Type: Liotina tryphenensis Powell.
Munditia delicatula n.sp. Pl. 28, figs. 1 and 2.
Shell minute, white, glossy, discoidal, widely umbilicate. Whorls 2 ¾, very rapidly increasing, including a low rounded smooth protoconch of 1½ whorls. Post-nuclear sculpture of prominent regularly-spaced axials, 15 on the last whorl. The body-whorl has in addition a very weak spiral thread at the angle of the shoulder and a stronger one towards the middle of the base. The lower spiral renders the axials somewhat thickened and sharply angled at the points of intersection. Umbilicus wide, perspective, slightly greater than one-fourth the major diameter of the base. Aperture circular, peristome with a thin raised inner margin, surrounded by a flange-like varix. Spire flat, suture impressed.
Height, 0·5 mm.; diameter, 1·05 mm. (holotype).
Holotype presented to Auckland Museum.
Locality: Between Spirits Bay and Three Kings Islands in 50 fathoms.
The species is allied to both owengaensis Powell, 1933, and manawatawhia Powell, 1937, but differs in being more depressed and in having only two spirals on the body-whorl.
Munditia anomala n.sp. Pl. 28, figs. 16 and 17.
Shell minute, discoidal, solid, white, bicarinate, closely radially striate. Whorls 3, including a small flattened protoconch of one whorl. Spire broadly rounded, very little raised. Peripheral carina projecting further than basal one, space between straight, oblique to axis. Umbilicus about one-fifth major diameter, deep, bounded by a ridge which is crenulated by the axial striae. Aperture circular, peristome with a smooth inner margin and bounded by a moderately heavy striated labial varix. The species resembles the genotype tryphenensis in shape and position of the keels, but there is a total absence of axial varices. Superficially it resembles a Lodderina.
Height, 0·45 mm.; diameter, 1 mm. (holotype).
Holotype in writer's collection, Auckland Museum.
Locality: Tom Bowling Bay, Northern New Zealand (in shell-sand).