Gonads & digestive tract, aboral view, from Agassiz, A. 1872. Revision of the Echini. Illustrated Catalogue of the Museum of Comparative Zoology 7.
Digestive tract & Aristotle's lantern, aboral view, from Agassiz, A. 1872. Revision of the Echini. Illustrated Catalogue of the Museum of Comparative Zoology 7.
