Tho`ra*cos"tra*ca (?), n. pl. [NL. See Thorax, and Ostracoid, a.] Zool.
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.
© Webster 1913.