Fissurella Alticosta

Fissurella alticosta, Conrad, Jour. Ac. Nat. Sc. vol. 7 p 142; Med. Ter. Foss. p. 78 pl. 44 fig. 7.

Subovate, with very prominent remote narrow ribs, about 18 or 20 in number, with intermediate unequal striae, the middle one largest; foramen large, subovate; inner margin crenelated, angulated at the ends of the ribs.

L. 1.3 H 0.65

Medial Tertiary