The Echinoid Directory

Pygmaeocidaris Doderlein, 1905, p. 621

Diagnostic Features	Test small (less than 15 mm diameter), tall and subconical, oral side flattened. Apical disc very large, dicyclic; genital plates pentagonal, ocular plates projecting and subtrigonal. Periproct opening small and central, circular, with five anal valve plates. No gonopores open in known specimens. Ambulacra trigeminate, with small oblique pore-pairs; weak phyllode developed on lowest two compound plates. Ambulacral plating arbaciid, with single large central element and two small demiplates. Interambulacral plates wide; primibasal plate present and prolonged with primary tubercle. Aboral plates without primary tubercles; covered in fine granulation and a few, small, irregularly scattered, rounded pustules. On oral surface one primary tubercle on ambulacral plates and two on interambulacral plates forming oblique series. No tubercles on apical side. Peristome about half test diameter. Single sphaeridium in perradial pit. Spines rather short, flattened, distally serrated.
Distribution	Recent, Indian Ocean.
Name gender	feminine
Type	Podocidaris prionigera Agassiz, 1879, p. 199, by original designation.
Species Included	Only the type species.
Classification and/or Status	Arbacioida, Arbaciidae. Monotypic.
Remarks	Like Codiopsis but distinguished from that genus by having small undifferentiated aboral pore-pairs rather than large subconjugate pore-pairs. Differs from Habrocidaris in having short but distinct phyllodes adorally, and compound plating that continues to the peristome margin. Döderlein, L. 1905. Über die Seeigel aus der Deutschen Tiefsee-Expedition. Zoologischer Anzeiger, 28, 621-624. Mortensen, T. 1935. A monograph of the Echinoidea II. Bothriocidaroida, Melonechinoida, Lepidocentroida and Stirodonta. C. A. Reitzel, Copenhagen