THE ACAEINA OR MITES. 



29 



The genus Myohia (fig. 32) was based on a species from the head of the house mouse. 

 ^ the legs are very short and thick, but the first pair are heavier than the others and 



■r,^^ on rr i 7 ■ -7 t^ i FiG. 30. — Harpyrvnchus longipilus: Larva. 



Tig. 2Q.—Harpyrijnchus longipilus: Female. ,, fj ^ .„ , f.^ , 



/ » *t , -1, ^ \-- s (Author's illustration.) 



(Author's illustration.) ^ . 



transformed into an organ fitted to grasp the hair. The eggs are fastened to the hair of 

 the mouse. The monph differs considerably from the larv^a and adult in the structure 



Yjg. 31.— Psorergates simplex. (Author's illustration.) Fig. 32.— J/yo&ia canadensis. (Original.) 



of legs and beak, the palpi being atrophied. In tliis stage it burrows into the hair 

 follicles, feeds there, and transforms. It is not supposed to suck the blood, but to 



