Phyllacanthus parvispinus
Eastern slate pencil urchin

Phylum: Echinodermata

Class: Echinoidea

Subclass: Cidaroidea

Order: Cidaroida

Family: Cidaridae

Subfamily: Cidarinae

Genus: Phyllacanthus

Species: parvispinus

Similar species:
Phyllacanthus irregularis