The Echinoid Directory

Porpitella Pomel, 1883, p. 72

Diagnostic Features	Small, ovate test depressed in profile and distinctly sunken sagittally. Apical disc anterior of centre with four gonopores. Petals small and rather rudimentary; pore-zones parallel and open distally - extending slightly more than half the radial distance to the ambitus. Ambulacral zones distinctly wider than interambulacral zones at ambitus. Peristome circular and central; somewhat sunken. No food grooves. Details of plating not known. Periproct opening on aboral surface near posterior margin. Tubercles on oral surface small and uniformly scattered, without bilateral symmetry. Fifteen internal radial partitions.
Distribution	Eocene, Europe, North Africa.
Name gender	feminine
Type	Cassidulus hayesianus Desmoulins 1791, by subsequent designation of Lambert, 1905, p. 136.
Species Included	P. hayesianus (Desmoulins, 1791); Eocene, France. P. concava (Thomas & Gauthier, 1881); Middle Eocene, Libya.
Classification and/or Status	Clypeasteroida; Scutellina; stem group laganiform or scutelliform. ?
Remarks	Like Lenita in being elongate with a sagital depression and posterior rostrum, but without the median naked zone or bilateral arrangement of oral tubercles. Porpitella and Lenita also distinctively have 15 internal radial buttresses. Pomel, A. 1883. Classification méthodique et genera des Échinides vivante et fossiles. Thèses présentées a la Faculté des Sciences de Paris pour obtenir le Grade de Docteur ès Sciences Naturelles, 503, 131 pp. Aldolphe Jourdan, Alger.