ORDER MALLOPHAGA 



85 



animal and open with a circular cap or lid at the free end. 

 The larvae are less flattened, shorter in proportion, and 

 without the hardened parts common to the adults, covering 

 a part or all of the surface. The length of life and rapidity 

 of multiplication has not been determined accurately for 



Fig. 46. — Trichodedes scalaris (biting cattle louse). (Bull. 5, Fig. 134.) 



these insects and the habits of the insects make any such 

 determination a matter of considerable difficulty. 



While it is, of course, very desirable that a more complete 

 knowledge of the life history of the species be secured, it 

 may be considered as already established that all the species, 

 with no know^n exception, pass their transformations on the 

 body of the fowl, and that, unlike the mites, they may be 



