The Echinoid Directory
Echinocystites pomum Thomson, 1861. Ludlow, Upper Silurian, Leintwardine, Herefordshire, England. Adapical (left) and adoral (right) ambulacral plating. From Hawkins, H. L. & Hampton, S. M. 1927. The occurrence, structure , and affinities of Echinocystis and Palaeodiscus. Quarterly Journal of the Geological Society London 83, 574-603, pls 44-46.