Slate Pencil Urchin
Pencil Sea Urchin
Eucidaris tribuloides

see larger image Slate Pencil Urchin Eucidaris tribuloides Tennessee Aquarium - Chattanooga, TN, USA © 2005 Jeff Whitlock use this photo see larger image Slate Pencil Urchin Eucidaris tribuloides Tennessee Aquarium - Chattanooga, TN, USA © 2007 Jeff Whitlock use this photo see larger image Slate Pencil Urchin Eucidaris tribuloides San Antonio Zoo - San Antonio, TX, USA © 2013 Jeff Whitlock use this photo see larger image Slate Pencil Urchin Eucidaris tribuloides San Antonio Zoo - San Antonio, TX, USA © 2014 Jeff Whitlock use this photo