

Pig. 56. — AstacHs furiatiHs. — The structure of the cuticle. .1. trans- 

 verse section of a joint of the forceps ( x 4) ; s, sette ; B, a por- 

 tion of the same ( x 80) ; C, a portion of B more highly magnified. 

 a. ppiostracum ; b, ectostracum : c, endostracum ; d. canal of seta ; 

 e, canals filled with air ; s, seta. D, section of an intersternal 

 membrane of the abdomen, the portion to the right in the natural 

 condition, the remainder pulled apart with needles ( x 20) ; U, 

 small portion of the same, highly magnified ; a, intermediate sub- 

 stance : b, laminae. F, a seta, highly magnified ; a and b, joints. 



