title: Slate pencil urchin
text: # 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
  