The Echinoid Directory

Contributed by Andrew Smith, February 2010

Eucidaris thouarsii (Agassiz & Desor, 1846, p. 326)

Diagnostic Features Distinguished from E. metularia by having its apical disc covered in fine tubercles (it is tubercle-free in E. metularia).  Distinguished from E. clavata by having longer more tapering spines (in E. clavata they are short and stout).  Distinguished from E. tribuloides by its narrow perradial band of tubercles between columns of pore-pairs (in E. tribuloides this zone is wider than one pore-pair in width and has secondary granules).
Distribution Recent, West coast of America from Lower California to Panama and the Galapagos and Cocos Islands; 0-45 m.
Classification and/or Status A species of Eucidaris
Remarks See Mortensen, T. 1928. A monograph of the Echinoidea. I. Cidaroidea. Copenhagen: C. A. Reitzel.