Dictionary entry

Thoracostraca

Webster's Dictionary 1913

‖Tho′ra‐cos″tra‐ca (?), n. pl. [NL. See Thorax, and Ostracoid, a.] (Zoöl.) An extensive division of Crustacea, having a dorsal shield or carapec� ��niting all, or nearly all, of the thoracic somites to the head. It includes the crabs, lobsters, shrimps, and similar species.