The Echinoid Directory

Pygidiolampas Clark, 1923, p. 345

Diagnostic Features	Test of medium length, subcircular with a pointed posterior margin, inflated, with a flat adoral surface Apical system subcentral, plating unclear. Kier (1962) reports that the apical disc is tetrabasal. From his photos of the holotype it would appear that there are four gonopores located outside the genital plates in the interambulacra, separated by small interambulacral plates, except in interambulacrum 5 where no gonopore is present Petals equal, broad, with wide interporiferous zones tapering distally. Pores conjugate, outer pores slit-like, inner pores circular; ambulacral plates beyond petals with single pores Peristome central pentagonal Periproct inframarginal, very small, longitudinal Bourrelets strongly developed, tooth-like; basicoronal plates longer than wide Phyllodes as broad arcs, single pored, with two series in each half ambulacrum Buccal pores present
Distribution	Upper Cretaceous (Campanian) of USA
Name gender	feminine
Type	Pygidiolampas eurynota Clark, 1923, p. 346; by original designation.
Species Included	P. eurynota Clark, 1923; Campanian, USA Kier (1962) also includes P. geometicus (Morton, 1834) in this genus.
Classification and/or Status	Irregularia; Cassiduloida; Faujasiidae; Faujasiinae Subjective junior synonym of Faujasia d'Orbigny, 1856.
Remarks	Pygidiolampas is very similar to Faujasia. Both genera have broad, equal petals, that are almost closed distally, subcircular tests, very similar floscelles, and apical systems where the gonopores are located outside the genital plates in the interambulacra. Kier (1962) reports that the apical disc in Faujasia is monobasal and in Pygidiolampas tetrabasal. In his photos of the holotype this is unclear, and should be treated with a degree of skepticism, particularly as Kier (1962) fails to mention that the gonopores are located outside the genital plates in the holotype of Pygidiolampas. We have therefore tentatively treated Pygidiolampas as a subjective junior synonym of Faujasia. P. M. Kier. 1962. Revision of the cassiduloid echinoids. Smithsonian Miscellaneous Collections, 144 (3) 262 pp.