CHAPTER XVI 



CRUSTACEA IN GENERAL 



The crayfish belongs to the order Decapoda, so-called be- 

 cause its members possess ten walking legs (five pairs). Most 



jr IG . 77 . — A, edible or blue crab; B, fiddler or soldier crab. (From 



Paulmier.) 



of the larger Crustacea are decapods; they not only are the most 

 important so far as our food supply is concerned, but many of 

 them are of great interest because of their peculiar habits and 



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