Fissurella, BRUGUIERE, 1789

Powell, Charles L. II & Geiger, Daniel L., 2019, Two new Miocene limpets (Fissurellidae) from southern California, with notes on other fossil occurrences of the family in northwestern North America, PaleoBios 36, pp. 1-7 : 2

FISSURELLA BRUGUIÈRE, 1789

Diagnosis —Shells are conical with an overall oval outline, with or without inclined sides, topped by a centrally-placed apex wholly absorbed by an oval foramen in mature specimens. The foramen is bordered inside by a ring of callus that is not truncated or excavated posteriorly. Sculpture is chiefly radial.

Type species — Fissurella nimbosa Linnaeus (1758) , by monotypy.

Remarks —The difference between Fissurella and the closely related genus Diodora is in the shape of the foramen at the apex and from the interior. In Fissurella the foramen is oval, while in Diodora the posterior end of the foramen is truncated. The interior of the shell described here is not available so the genus determination is questioned.