i8 



ELEMENTARY ZOOLOGY 



antennule 



opening of green gland 



maxillipeds----f- 



thorax 



genital aperture 



.'' anus 



,.,-"uropod 



telson 



JT IG . 3. Ventral aspect of crayfish (Cambarus sp.), with the appendages ot 

 one side disarticulated. 



