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INSECTS CRUSTACEA DIAGRAM 



CLASS CRUSTACEA, 



The Crustacea , "with the insects Arachnida, and Myriapoda, 

 form the great division of articulate animals, that is, animals 

 formed of segments. The Crustacea may be easily known by 

 always having more than four pairs of legs ; they have ten, as in 

 the crayfish and crab, or a much greater number ; the wood-louse, 



Crab. 



for instance, has fourteen. Crustacea, like insects, have lateral 

 jaws, and eyes in which the facets may easily be seen, but they 

 never breathe by trachea?; they have branchia like fish. They 

 undergo frequent moults. 



The Crayfish. In. the crayfish the head and thorax are united. 



