Slate pencil urchin
# Slate pencil urchin

Slate pencil urchin is a common name for several sea urchin species with blunt spines:

* Eucidaris, a genus with several tropical species, especially:
   * Eucidaris thouarsii, an East Pacific species
   * Eucidaris tribuloides, an Atlantic species
* Heterocentrotus, a genus with two Indo-Pacific species
