Perisome
Full definition of perisome
Noun
perisome
(plural perisomes)- (biology) The outer body of an invertebrate; the integument
- 1878, Carl Gegenbaur, Elements of Comparative Anatomy, In many Echinoïda, as in the Asteroïda, the calcareous plates of the perisome are movably connected together, and so allow of changes in the form of the body.