5. 2 n . d Maxilla 6. Ir Maxillibe d 



Q.Copuldfory Organs 10. Swim mm g Fo of 



FIG. 91. Typical appendages of the Fresh-water Crayfish, placed in the same 

 position, with the protopodite (fir) and epipodite (ep} downwards, the endopodite 

 (en) to the left, and the exopodite (ex) to the right. 



The protopodite is typically formed of two podomeres (pr. T.,pr. 2), the endopodite 

 of -five (en. i en. 5) ; a gill (g) may be attached to the epipodite. 



The three proximal segments of the antennule are marked, i 3, its flagella ft. i 

 and./?. 2 ; the distal end of the endopodite of the antenna is a flagellum (y?). 

 (The tufts of threads in 7 and 8 are very long setae which extend between the 

 gills). (From Parker and Haswell's Zoology, after Huxley.) 



The structure of these appendages is best understood by 

 a consideration of the third maxilliped (Fig. 91, 7). The 

 main portion of the limb is formed of seven podomeres 



