Thoracostraca
Thoracostraca , noun, plural
[New Latin See Thorax, and Ostracoid, a.]
(Zoology) An extensive division of Crustacea, having a dorsal shield or carapec{not transcribed}niting all, or nearly all, of the thoracic somites to the head. It includes the crabs, lobsters, shrimps, and similar species.