164- 



THE MORPHOLOGY OF THE COMMON CRAYFISH. 



The third niaxillipede is one of the most complete of 

 these appendages, and may be advantageously made the 

 starting point of the study of the whole series. 



Fig. 44 — Astac7ift fluriatilis. — The third or external maxillipede of the 

 left side ( x 3). e, lamina, and hr, branchial filaments of the 

 podobranchia ; cxjk coxopodite ; cxs, coxopoditic setae ; hp, basi- 

 podite ; ex, exopodite ; ijJ, ischiopodite ; mj), meropodite ; gjj, 

 carpopodite ; 2Uh propcdite ; dj), dactylopodite. 



Neglecting details for the moment, it may be said that 

 the appendage consists of a basal portion (fig. 44, cxp, hp). 



