The Echinoid Directory

Pliolampas Pomel, 1888, p. 446

[=Breynella Gregory, 1891, p. 600, type species Pygorhynchus vassalli Wright, 1855; =Milletia Duncan 1891, p. 191, type species Echinolampas elegantulus Cotteau, 1883 ]

Diagnostic Features	Test of medium size, elongate, moderately inflated, with pointed posterior margin, flat adoral surface slightly sunken towards peristome. Apical system monobasal with three genital pores, pore absent in left anterior genital plate. Petals well developed, open, broad, equal, with broad poriferous zones. Pores conjugate, ambulacral plates beyond petals with single pores. Peristome, anterior, longer than wide, pentagonal; sunken. Periproct inframarginal, ovate and transverse. Bourrelets weakly developed, forming slightly convex walls to the peristome entrance. Phyllodes broadened adorally, single pored, with outer series and a few pores in a short inner series. Buccal pores present. Tubercles slightly larger adorally, no naked granular zone adorally in interambulacrum 5.
Distribution	Eocene to Miocene of Europe and the circum-Mediterranean countries.
Name gender	feminine
Type	Echinolampas gauthieri Cotteau, 1880, p. 227; by monotypy.
Species Included	P. dilatatus Callegari, 1930; Helvetian, Italy. P. gauthieri (Cotteau, 1880); Middle Miocene, France. P. elegantulus (Cotteau, 1883); Miocene France. P. pioti Gauthier, 1899; Miocene, Egypt. P. trevisani Checchia-Rispoli, 1936; Eocene, Sicily. P. vassalli (Wright, 1855); Miocene, Malta.
Classification and/or Status	Irregularia; Cassiduloida; Neolampadidae. Name proposed to replace Plesiolampas Pomel, 1883, non Duncan & Sladen, 1882.
Remarks	There has been considerable controversy over the number of genital pores in this genus. Kier (1962, p. 193) states that after studying the type specimen he is uncertain whether there are three or four genital pores, as the apical disc is poorly preserved. Kier (1962) also remarks that the number of genital pores in Pliolampas pioti Gauthier, 1899 is variable, with either three or four genital pores present. Gauthier in Fourtau (1899) reports that this species typically has three genital pores, with a single exception, where a specimen was found with four genital pores. V. Gauthier in R. Fourtau. 1899. Revision des echinides fossiles de l\'Egypte. Memoires de l\'Institut Egyptien, 3, 605-740, pls 1-4. P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections 144, (3), 262 pp. Pomel, A. 1888. Bulletin de la Societe geologique de France serie 3, 16, p. 446.