Genus Maoricrypta Finlay, 1926.
Type: Crepidula costata Sowerby.

Maoricrypta salebrosa n. sp. (Figs. 50, 51.)

Shell of moderate size, strongly convex, relatively high and narrow. Beaks strongly incurved, twisted well to the side and separated from the apertural margin by wide space covered with growth-lines. Sculpture of about 12 to 16 rounded, irregular, gnarled, spiral ridges with equal or wider interstices. These ridges generally stronger along crest of shell and narrower on outer or left side than on inner or right side. Growth-lines irregular. Septum extending about halfway along shell, a little further on left than right; anterior margin gently concave, with very shallow sinus in middle.

Holotype in Dominion Museum.

Height, 17 mm.; length, 40 mm.; width, 23 mm.

The sinuosity of the septal margin is rather better marked in this species than in the others of the group, i.e., M. costata Sowerby, M. wilckensi Finlay, etc., and is very different from that of the type of Crepidula, C. fornicata L. In Crepidula the septal margin follows a shallow sigmoid curve, in Maoricrypta it is gently concave with a shallow median sinus.