T 



Legs of 1st 

 pair 



cheliform. 

 distinctly 



Uropoda terminal. Pleopoda, whenj ^ „, ,.„ 

 developed, exclusively natatory. J 



not cheli- 

 form. 



Uropoda 

 lateral. 



Uropoda 

 terminal. 



forming together with the 

 terminal segment of the 

 metasome a caudal fan. 

 Pleopoda for the most part 

 natatory. 



valve-like, inflexed, arching 

 over the pleopoda, which 

 to a great extent are bran- 

 chial. 



Pleopoda exclusively bran- 

 chial, generally covered by 

 a thin opercular plate (the 

 modified 1st pair.) 



Pleopoda fitted for air-1 

 breathing. 



Pleopoda, when present, ex- 

 clusively branchial in the 

 adult animal, and not cov- 

 ered by any operculum. 



2. Flabellifera. 



3. Valvifera. 



4. Asellota. 



5. Oniscoidea. 



6. Epicarida. 



