<p><strong>Fig. 3.87.</strong> (<strong>C</strong>) Blunt spines on a red slate pencil urchin (<em>Heterocentrotus mammillatus</em>)</p>

Fig. 3.87. (C) Blunt spines on a red slate pencil urchin (Heterocentrotus mammillatus)

Image courtesy of Scott Roy Atwood, Wikimedia Commons