entomostraca
En`to*mos"tra*ca, n. pl. Etym: [NL., fr. Gr. (Zoöl.) Defn: One of the subclasses of Crustacea, including a large number of species, many of them minute. The group embraces several orders; as the Phyllopoda, Ostracoda, Copepoda, and Pectostraca. See Copepoda, Phyllopoda, and Cladocera.