The Crayfish. 



35 



between the thoracic appendages of the lobster and the cray- 

 fish, that the thoracic limbs of the latter consist of protopodite 

 and endopodite. We next come to a set of limbs which sub- 

 serve the function of manducation : they assist in comminuting 



Fig. i6.— Thoracic limb of Crayfish. (After Huxley.) 

 hr podobranchi cxp, coxopodite; hp, basipodite ; ip, ischiopodite ; ntp, meropodite ; 

 c/, carpopodlte ; pp, .propodite ; dp, dactylopodite ; cx.s, coxopodite sets ; e, epipodite. 



the food. Here again we should expect to find what we do 

 find, that a difference of function is accompanied by a differ- 

 ence of structure. These limbs are termed^those next to the 



