The Echinoid Directory

• Test subovate, of small to medium size, broad with greatest width posterior to centre; oral surface slightly sunken towards the peristome.
• Apical system slightly anterior, tetrabasal, with four gonopores, no catenal plates, short posterior ocular plates (advanced form).
• Petals narrow, open, tapering distally, extending two-thirds distance to ambitus, inner pore round, outer pore slightly elongated transversely; all ambulacral plates double pored.
• Periproct supramarginal, longitudinal, opening into anal sulcus extending from periproct to posterior margin.
• Peristome anterior, pentagonal, depressed, equant.
• Bourrelets absent.
• Phyllodes slightly widened, double pored, with an inner and an outer series of rounded pores in each half ambulacrum.
• No buccal pores.
• No naked zone in posterior interambulacrum orally.

Bajocian (Middle Jurassic) to Cenomanian (Late Cretaceous) of Europe.

Echinobrissus lorioli Cotteau, 1871, p. 236; by subsequent designation of Lambert, 1898, p. 468.

• C. lorioli (Cotteau, 1871); Late Bajocian-Callovian, France
• C. micraulus (L. Agassiz, 1839): Callovian, Europe

Lambert & Thiery (1909-1925) list 53 nominal species within this genus.

Irregularia; Neognathostomata; 'nucleolitid'.

Subjective junior synonym of Nucleolites Lamarck, 1801.

There are no diagnostic features to differentiate Clitopygus from Nucleolites.

G. Cotteau. 1867-1874. Paleontologie francaise ou description de fossiles de la France. Terrain Jurassiques. Tome IX. Echinoidea. G. Masson, Paris. 552 pp., pls. 1-142.

J. Lambert & P. Thiery. 1909-1925. Essai de nomenclature raisonnee des echinides. Libraire Septime Ferriere, Chaumont, 607 pp., 15 pls.

Pomel. A. 1883. Classification méthodique et genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles, 503, 131 pp. Aldolphe Jourdan, Alger.