En'to-mōs'-tra-cān, n.

n. [Gr. ἔντομος, cut in, and ὀστρακὸν, burnt clay, the hard shell of testacea; Fr. entomostracé. See supra.] Entomostomata. 1. Ricinula horrida. 2. Cancillaria reticulata. (Zoöl.) A crustacean of inferior grade. See CRUSTACEAN. ☞ The principal subdivisions of the Entomostracans are, I. Those with an excessive multiplication of legs, as in the Branchipus, Simmodia, &c. II. Those with the number of legs not exceeding the normal number; and here the greater part of the species are included. The Cyclops tribe contains minute species, somewhat shrimplike in form; the Cypris tribe, those in which the body is inclosed in a bivalve shell; the Daphnia tribe is similarly bivalve, but the valves are not closed and the head not included; the Caligulus tribe, fish-lice, have a suckermouth and a regular series of legs; the Lernæa tribe, fish-lice with legs, mostly obsolete; the Limulus tribe, of which the horse-shoe is a species, have no jaws, but the basal joints of the legs surround the mouth and serve the purpose of ordinary teeth in masticating food. Dana.