The Echinoid Directory

• Test small, depressed, weakly subconical in profile.
• Apical disc dicyclic; firmly bound to corona. All plates covered in pustular granules.
• Ambulacra simple adapically with one to three granules on each plate; pore-pairs small, oblique and uniserially arranged. Immediately beneath ambitus two or three trigeminate plates with large tubercle covering two of the three elements; tubercles and plating continues like this to peristome.
• Interambulacral plates a little wider than tall. On aboral surface, plates uniformly covered in fine secondary tubercles with no primaries differentiated. Art ambitus and adorally each plate bears a large primary tubercle that is imperforate, noncrenulate and with a large mamelon.
• Peristome slightly sunken, about 50% test diameter. Buccal notches open and shallow.
• Spines and lantern unknown.

Pleurodiadema gauthieri Cotteau, 1875, p. 189. Syntypes (2): Museum National d'Histoire Naturelle, Paris J01518.

Euechinoidea, Echinacea, Arbacioida, Glyticidae

Monotypic; Subjective junior synonym of Pleurodiadema de Loriol, 1870.