Lacuna pallidula

(da Costa, 1778)

Description (shell):
Shell globular, thin and smooth, with three or four rapidly expanding whorls; sutures deep. Last whorl occupies most of spire; aperture very large, almost equal to shell height. Umbilicus deep, open, revealing much of interior surface of spire; umbilical groove wide (wider in males than in females), with longitudinally ridged surface (L. pallidula-drawing).

Up to 12 x 6 mm in females, 6 x 3 mm in males.

Yellowish green, occasionally white; unbanded.

Body as in Lacuna vincta : snout long, broad, with slender cephalic tentacles arising from base. Foot elongate, with double edged anterior margin; two short, flat metapodial tentacles project from below operculum.

On seaweeds at LWST, extending sublittorally to 70 m.

Distribution similar to that of Lacuna vincta: a circumboreal species extending south in Europe as far as the Channel and, less frequently, the Atlantic coasts of France. On suitable weed-covered shores on all British and Irish coasts and off Helgoland (Distr. L. pallidula).