The Echinoid Directory

Phaleropygus de Loriol, 1902, p. 15

Diagnostic Features	Test of small to medium size, oval, elongate, moderately inflated, with a smoothly rounded anterior margin and a truncated and notched posterior margin. Oral surface depressed towards peristome. Apical system subcentral, monobasal, probably with four genital pores. Petals long, parallel, open, but with a tendency to taper distally. Inner pores round, outer pores slightly elongated transversely. Peristome slightly anterior, longer than wide. Periproct marginal, longitudinally oval, invaginated, very large. Bourrelets only slightly developed. Phyllode development unknown.
Distribution	Miocene of France.
Name gender	masculine
Type	Phaleropygus oppenheimi de Loriol, 1902, p. 15; by monotypy.
Species Included	Only the type species.
Classification and/or Status	Irregularia; Cassiduloida; \'Gitolampadids\' Possible subjective junior synonym of Gitolampas Gauthier, 1889. [or Rhopostoma]
Remarks	Lambert & Thiery (1909-1925, p. 372) and Kier (1962, p. 217) consider Phaleropygus a synonym of Studeria. Mortensen (1948, p. 335) correctly points out that in de Loriol\'s diagnosis he states that there are four genital pores, which prevents it being identical to Studeria which has only three. However, in de Loriol\'s description of the type species he states that there are "probably" four genital pores. It is this description that has lead to the uncertainty of whether Phaleropygus is synonymous with Studeria. The type species of Phaleropygus and Gitolampas appear to be similar, each having a monobasal apical system, with probably four genital pores, an eccentric peristome and slightly to moderately developed bourrelets. Both species also have a very similar invaginated periproct on a truncated posterior margin. The petals appear to be slightly more developed in the type species of Gitolampas, however, such a slight difference is not worthy of generic distinction. The phyllode development in Phaleropygus is not known, if this is found to be similar to Gitolampas then Phaleropygus should be considered a junior subjective synonym of Gitolampas. P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144, (3), 262 pp. Loriol, P. de 1902. Notes pour servir à l’étude des échinodermes, 10. 32 pp., 4 pls. Georg, Basle & Genève.