The Echinoid Directory

Key to the genera of Maretiidae - 1

1a. Apical disc with three gonopores.
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1b. Apical disc with four gonopores.

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2a. Paired ambulacra with fully formed petals; pore-pairs conjugate.

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2b. Paired ambulacra subpetaloid; pore-pairs small and not conjugate.
Homolampas

3a. Petals obviously sunken.

Tripatagus

3b. Petals more or less flush.

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4a. Sternal plates (outlined in yellow) tubercle-free in their anterior half.
Hemimaretia

4b. Sternal plates tuberculate over most of their surface.

Nacospatangus