The Echinoid Directory

Globiferous pedicellaria showing complete structure in Psammechinus (right) and an isolated valve of Echinus in internal and lateral views. From Mortensen, T. 1943. A Monograph of the Echinoidea. Camarodonta 2. III(3). C. A. Reitzel, Copenhagen.

b = blade; et = end tooth; lt = lateral tooth; s = poison sac; st = stalk