Diagnostic characters
Shell small, with low spire (apical angle 110-115°), slight periostracum, and large aperture (round in males, higher than broad and with a slight basal spout in females). Columellar groove marked with longitudinal ridges. Brownish, apex sometimes purplish; without colour bands.
Other characters
The shell is delicate, has three tumid whorls meeting at deep sutures below which they are a little flattened; the last whorl is often slightly angulated below the periphery. Up to 4mm high, 4mm broad; last whorl occupies about 90% of shell height, aperture about 70%.
The animal resembles L. vincta. It is cream, the head pinkish with white tentacles, the sides of the foot grey.
L. parva occurs in the same situations as L. vincta but often somewhat higher on the shore, on Fucus serratus, F. vesiculosus and on red weeds, which, with their epiphytic growths, form its food. The animals are found on European shores from the Arctic Ocean to Iberia and on all suitable shores in the British Isles. The spawn is a hemispherical, clear mass of jelly fastened to weeds, preferably Phyllophora; it is about 2 mm in diameter and contains about ten eggs which hatch as juvenile snails (Ockelmann & Nielsen. 1981). The animals are annuals. Vernacular name: chink shell.