The Echinoid Directory

Plagiechinus Pomel, 1883, p. 78

[= Diplosalenia Mortensen, 1942, p. 232, type species Parasalenia grosseleti Cotteau, 1894 ]

Diagnostic Features	Apical disc unknown. Test oval in outline, with long axis in unknown orientation. Ambulacral plating trigeminate, with pore-pairs arranged in an arc. One large primary tubercle to each ambulacral plate. Interambulacral plates with primary tubercle and slightly smaller secondary tubercle adradially. All tubercles imperforate and non-crenulate. Buccal notches small; phyllodes not strongly developed. Peristome relatively large (> half test diameter).
Distribution	Upper Oligocene (Chattian) to Lower Miocene (Aquitanian); Carribean.
Name gender	masculine
Type	Echinometra prisca Cotteau, 1875, p. 12, by original designation.
Species Included	Only the type species.
Classification and/or Status	Camarodonta; Echinoida; Echinometridae. Monotypic, possibly a junior subjective synonym of Parasalenia.
Remarks	This species has an elliptical test which suggests relationships to either Echinometra, Colobocentrotus or Parasalenia. Unfortunately, no specimen has been seen which retains apical disc plates, and thus the axis of elongation cannot be determined. Its correct generic placement cannot therefore be determined. However, only Parasalenia has trigeminate ambulacral plate compounding. 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.