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DescriptionSmall urchin with large spines with rows of 'thorns'. Test 6cmØ, thick primary spines 10cm long (1.5x testØ). Primary spines mainly smooth on one side, with thorns forming 5 rows on the other three sides. The thorns are well spaced along most of the length, but develop into five blade-like ridges about 1cm from the tip. The thorns are not aligned to form rings around the spines. Interambulacral area very wide and densely covered with small miliary spines.