Crustacea

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Crustacea \Crus*ta"ce*a\ (kr?s-t?"sh?-?), n. pl. [Neut. pl. of
     NL. crustaceus pert. to the crust or shell, from L. crusta
     the hard surfsce of a body, rind, shell.] (Zool.)
     One of the classes of the arthropods, including lobsters and
     crabs; -- so called from the crustlike shell with which they
     are covered.


     [1913 Webster]
  
     Note: The body usually consists of an anterior part, made up
           of the head and thorax combined, called the
           cephalothorax, and of a posterior jointed part called
           the abdomen, postabdomen, and (improperly) tail. They
           breathe by means of gills variously attached to some of
           the limbs or to the sides the body, according to the
           group. They are divisible into two subclasses,
           Entomostraca and Malacostraca, each of which includes
           several orders.
           [1913 Webster]

From WordNet (r) 2.0 [wn]:

  Crustacea
       n : class of mandibulate arthropods including: lobsters; crabs;
           shrimps; woodlice; barnacles; decapods; water fleas [syn:
            {class Crustacea}]