36 



Elementary Zoology. 



ambulatory limbs — the maxillipedes, consisting of three pairs; 

 then follow two pairs of maxilla, and finally a single pair of 

 mandibles. The maxillipedes, as their name denotes, are not 

 exclusively manducatory appendages ; they are partly ambu- 

 latory, and are intermediate in structure. They are, however, 

 more " typical " in their formation than the ambulatory 

 appendages. They are all biramous. The last pair (see 



Fic. 17 — Third maxillipede of Crayfish. (After Huxley.) 

 ex, exopodite ; other letters as in Fig. 16. 



Fig. 17) has a protopodite and an endopodite much like 

 that of the ambulatory limb ; the details of difference can be 

 gathered from an inspection of the figure. But it has, in 

 addition, an exopodite, shorter than the endopodite, and 

 ending in a flagellum like that of the swimmerets. The pair 

 of appendages in front of this, the second maxillipedes 



