The Echinoid Directory

Ova Gray, 1825, p. 431

[=Nina Gray, 1855, p. 60 (objective). ]

Diagnostic Features	Test ovate with deep anterior sulcus; slightly pointed to rear and carinate. Apical disc ethmolytic, with 2 gonopores; anterior genital plates imperforate. Anterior ambulacrum deeply sunken adapically, becoming less pronounced towards the ambitus; pore-pairs specialized and associated with funnel-building tube-feet. Pore-pairs in offset double column on each side of wide groove in the type species, but uniserially arranged in other species. Other ambulacra also deeply sunken, anterior petals much longer and more flexed than posterior petals. Periproct small and marginal, on near-vertical truncate face. 5-7 subanal penicillate tube-feet. Peristome labiate; wider than long. Labral plate short and wide; in broad contact with sternal plates; not reaching start of ambulacral plate 2 at rear. Plastron wide and ovate, episternal plates not paired and opposite and not forming significant part of plastronal area. Aboral tuberculation fine, uniform and dense. Well-developed peripetalous and latero-anal fascioles.
Distribution	Eocene to Recent, cosmopolitan.
Name gender	feminine
Type	Spatangus canaliferus Lamarck 1816; SD ICZN op. 209, 1948 [non Ova Pomel 1887, p. 701; (=Nina Gray, 1855, p. 60)].
Species Included	Includes many of the species formally classified as Schizaster, including: O. subcylindricus; Eocene, Cuba. O. saheliensis (Pomel, 1887); Upper Miocene - Pliocene, circum Mediterranean. O. lacunosus (Linnaeus, 1758); Recent, Indo-Pacific. O. edwardsi Cotteau, 1889; Recent, east coast of Africa. O. orbignyanus Agassiz, 1880; Recent, north west Atlantic. O. desori Wright, 1855; Miocene, Mediterranean. O. canaliferus (Lamarck 1816); Recent, Mediterranean.
Classification and/or Status	Spatangoida, Paleopneustina, Schizasteridae. Monophyly suspect.
Remarks	Differs from Schizaster in having two gonopores rather than four. In the pore-pairs of the frontal groove are uniserially arranged except in the type species where pore-pairs are arranged as a double column. Hypselaster is very similar but has an incomplete latero-anal fasciole. Gray, J.E. 1825. An attempt to divide the Echinida, or sea eggs, into natural families. Annals of Philosophy, new series, 10, 423-431. Mortensen, T. 1951. A monograph of the Echinoidea V. Spatangoida 2. C. A. Reitzel, Copenhagen.