The Echinoid Directory

Oeidolampas Lambert, 1918, p. 38

Diagnostic Features
  • Test of moderate size, subovate in outline, inflated, with a relatively flat adoral surface, slightly sunken towards the peristome.
  • Apical disc subcentral; monobasal, with four gonopores.
  • Petals well developed; broad, slightly bowed and open distally. Inner pores round, outer pores elongated transversely; pore-pairs subconjugate. The two columns in each petal of unequal length, extending almost to ambitus.
  • Peristome anterior, subpentagonal, wider than long.
  • Periproct inframarginal and transverse; not sunken.
  • Phyllodes short but strongly developed, single pored, with three series in each half ambulacrum, plus scattered pores in between.
  • Bourrelets slightly developed, with a distinct well leading to the peristome opening.
  • Buccal pores present.
Middle Eocene of France.
Name gender feminine
Echinolampas ataxensis Cotteau, 1889, p. 80; by original designation.
Species Included
  • O. ataxensis (Cotteau, 1889); Middle Eocene, France
Classification and/or Status

Irregularia; Cassiduloida; Echinolampadidae

Subjective junior synonym of Echinolampas Gray, 1825.


Oeidolampas has all the diagnostic characters of Echinolampas, with well developed, asymmetric petals (the two pore series in each petal of unequal length), an inframarginal periproct on a relatively flat adoral surface that is slightly sunken towards the peristome, and weakly developed bourrelets. Oeidolampas differs slightly from the subgenus E. (Echinolampas) as it is reported to have three distinct series of pore-pairs in its phyllodes.

G. Cotteau. 1889-1894. Paleontologie francaise. Terrain tertiaire. II. Echinides eocenes. Paris, G. Mason. 789 pp., pls 201-384.

P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 144 (3) 262 pp.

Lambert, J. 1918. Considérations sur la classification des échinides atelostomes. Mémoires de la Société académique de l’Aube, (3) 82, 9-54.