The Echinoid Directory

Key to genera of Urechinidae

1a. Two discrete anterior genital plates.

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1b. Single anterior genital plate.

Cystechinus

2a. Periproct marginal (arrowed) ; four gonopores; females with modified brood pouch.

Antrechinus

2b. Periproct inframarginal (arrowed); three gonopores; no sexual dimorphism.

Urechinus