perisoma

Century Dictionary and Cyclopedia

1. n. The body-wall of an echinoderm; the parietes of the perivisceral cavity (the modified enterocœle of the larva) in the Echinodermata. The mesoderm presents a more or less radially disposed set of antimeres, while the ectoderm may develop a coriaceous or calcareous exoskeleton. See cuts under Holothuroidea and Synapta. Also perisome.

Wiktionary

1. n. zoology A perisome.

GNU Webster's 1913

1. n. (Zoöl.) Same as perisome.