The Echinoid Directory

Contributed by Andreas Kroh, July 2008

Solenocystis Mironov, 2008, p. 13

Diagnostic Features	Test bottle-shaped with long posterior rostrum, lacking a neck, thin-shelled. Apical disc disjunct, posterior ocular. plates pores separated by a pair of interambulacral plates. Four gonopores, posterior ocular pores absent or indistinct. Plastron disjunct; labrum large, separated from the sternal plate by two symmetrical pairs of plates; episternal plates paired. Plastron and latero-anterior part of oral surface densely covered in tubercles, aboral side sparsely tuberculated. Periproct supramarginal, in deep invagination. Subanal fasciole present. Only tridentate pedicellariae of small and medium size occur on most of the test. Large tridentate and globiferous pedicellariae are restricted to the periproctal invagination. Stalk globiferous pedicellariae with large thorns. Rostrate and ophicephalous pedicellariae absent.
Distribution	Recent; Northern Atlantic.
Name gender	feminine
Type	Solenocystis imitans Mironov, 2008, p. 16, by original designation. RV G.O. Sars, MAR-ECO expedition, St. 72/386 (27 July 2004, 53 degrees16'N, 35 degrees 31'W, 2555-2517 m), Northern Atlantic Ocean; Holotype: Museum of Zoology, University Bergen, MAR-ECO 008141.
Species Included	Only the type species.
Classification and/or Status	Holasteroida, Meridosternata, Urechinina, Pourtalesiidae.
Remarks	Differs from Pourtalesia by its large labrum. Differentiated from Helgocystis by the presence of two plate pairs separating labrum and sternal plate, and labrum shape (triangular in Helgocystis). Differs from Echinosigra (Echinosigra) by its test shape (lack of a neck) and presence of 4 gonopores. Distinguished from Echinosigra (Echinogutta) by its test shape (lack of a neck) and the presence of two plate pairs separating labrum and sternal plate. Mironov, A. N. 2008. Pourtalesiid sea urchins (Echinodermata: Echinoidea) of the northern Mid-Atlantic Ridge. Marine Biology Research 4(1-2): 3-24.