CRUSTACEA

(Lat.), n. n. pi. Kiai3st(kru<st)-a(as)'se!(ke)-a'. Fr., crustaces. Ger., Crustaceen, Krebs, Kruxtenthier. 1. Of Linnaeus, a cla of Aptera. [L, 43.] 2. Of Cuvier and Owen, a cla of the Articulata (of Lankester, of the Acerata). animals characterized by "a chitinous or sub calcareous exoskeleton," the division of the body into a variable number of somites usually 21 some or all of which are provided with a pair of articulated appendages, and, as a rule, a respiratory apparatus adapted to an aquatic life. The sexes are distinct except in the Cirriped i a, but the young usually undergo a metamorphosis after leaving the ovum. They are generally divided into the subcla es Entomostraca and Mala cost raca. [L, 11, 121, 147, 168.] [s. 455]