Mites Injurious to Domestic Animals. 69 



laterally like the insects of the family Pulicidae (fleas), in order to 

 enable them to progress rapidly through the fur of the host. 

 Distinct tracheal tubes are present in some Listrophorid mites 

 (fig. 34). (See Hirst, Journ. Quekett Club, November, 1921.) 



Listrophorus gibbus, Pag., is often very abundant in the fur of 



FIG. 57. 



Dermanyssus gallinae (p. 87). Ventral view of male, X 123. 

 (Original.) 



rabbits. Another species (L. mustelae) is found on ferrets. A 

 minute Listrophorid mite (Chirodiscoides caviae, Hirst, fig. 35) 

 attaches itself to the hairs on the back of guinea-pigs. 



It is said that some of the species of Listrophorus are preyed 

 upon by species of Cheyletinae, which use the rabbit's fur as a 

 hunting forest. 



