The Echinoid Directory

Contributed by Andrew Smith, December 2006

Arialopsis Lambert & Thiery, 1925, p. 566

[=Stephanopsis Lambert, 1900, p. 29, non Stephanopsis Cambridge, 1869; = Stephomma Stechow 1921, p. 263 (objective)]

Diagnostic Features	Test subpentagonal; slightly depressed on the oral surface. Apical disc monocyclic with quadrangular periproctal opening. Peristome very large. Ambulacra straight and plating trigeminate. Interambulacral plates with central primary tubercle flanked by inner and outer secondary tubercles; other granulation sparse.
Distribution	Upper Cretaceous (Campanian-Maastrichtian), southern India
Name gender	feminine
Type	Orthopsis similis Stoliczka, 1873, p. 46.
Species Included	Only the type species.
Classification and/or Status	Replacement name for Stephanopsis Lambert, 1900, p. 29, non Stephanopsis Cambridge, 1869. An objective junior synonym of Stephomma Stechow, 1921, p. 263 Subjective junior synonym of Orthopsis Cotteau, 1864
Remarks	Stechow (1921, p. 263) had already realized that Lambert's name Stephanopsis was preoccupied and had proposed the name Stephomma as a replacement which thus has seniority. Established as a subgenus of Orthopsis Cotteau, 1864. Separated by Lambert & Thiery on the basis that its apical disc was illustrated as monocyclic. This needs to be confirmed by restudy of the holotype. Lambert, J. & Thiery, P. 1909-1925. Essai de nomenclature raisonnee des echinides. Chaumont, Paris. Stoliczka, F. 1873. Cretaceous fauna of southern India. The Echinodermata. Memoirs of the Geological Survey of India. Palaeontologia Indica IV.3, Series VIII.3. 71-129, pls 1-7.