Semicassis labiata

Semicassis labiata is a species of large predatory sea snail, a marine gastropod mollusc. This species is in the subfamily Cassinae, the "helmet shells" and "bonnet shells", which feed on sea urchins.

Distribution

This species is found around the northern part of the North Island of New Zealand, and in south eastern Australia including Norfolk Island.

Habitat

This sea snail lives in shallow water.

Shell description

The shell is moderately large, fairly solid, ovate, smooth and polished without nodules. When adult, it has a thick, rounded labial varix, denticulate along its inner edge. The inner lip callus shield is thick and adpressed, bridging a very small umbilical chink.

The shell coloration is pale brown to bluish-grey, with a complicated pattern of reddish-brown axial streaks, crossed by revolving bands of irregular, sometimes chevron-shaped, brown maculations, interspersed with pale areas of ground colour. The tip of the spire is pink, the labial varix is banded with purplish-brown, the interior of the aperture is chestnut, and the inner lip callus is light brown to pale orange.

The maximum shell height is 83 mm, and width 52 mm.

References

• Powell A. W. B., William Collins Publishers Ltd, Auckland 1979 ISBN 0-00-216906-1