The Echinoid Directory

• Test bottle-shaped with strong posterior rostrum; thin-shelled.
• Apical disc with four gonopores. Compact, with single anterior plate bearing two gonopores (G2) and two postero-lateral plates each with a gonopore (= ocular plates II and IV). Posterior genital plates rudimentary or lost. Posterior ocular plates far removed from remaining plates of apical disc.
• Ambulacra all similar with minute pores only outside oral region.
• Anterior ambulacrum deeply sunken from ambitus adorally, forming a funnel-like opening to the peristome.
• Peristome subcircular and facing anteriorly into frontal groove.
• Plastron plating orthosternous; first sternal plate followed by a pair of symmetrical episternal plates.
• Plastron disjunct. Lateral ambulacra also disjunct, with plates of interambulacra 1 and 4 intercalated.
• Scattered small tubercles distributed over the aboral surface.
• Periproct supramarginal, overarched by interambulcral plates forming a hood.
• Subanal fasciole present at end of rostrum.

Recent; Pacific.

Pourtalesia laguncula Agassiz, 1879, p. 205, by original designation.

• Only the type species.

Holasteroida, Meridosternata, Urechinina, Pourtalesiidae.

Subjective junior synonym of Pourtalesia A. Agassiz, 1869