About Petricolaria pholadiformis (Lamarck, 1818)
Petricolaria pholadiformis closely resembles the angel wing (Cyrtopleura costata). The main distinguishing feature is that it lacks the apophyses — the spoon-shaped wings located near the beak — that true angel wings have. This species grows to about 5 centimetres (2.0 inches) long, and is usually white in color. Its anterior end is extended and ends in a rounded point, while its posterior end is blunt and curved. Ridges radiate out from the beak; these ridges are more pronounced at the posterior end. Fainter growth rings run parallel to the shell margin.
