ITCH MITES. 



309 



CASE koptes) for Psoroptes, or Dermatodectes, seems to be altogether 

 without justification, and he offers none. 



The genus is easily characterised. It is not a burrowing mite ; 

 and, in accordance with its habits, it has lance-like mandibles 



Pboroptes equi. Two posterior 

 legs of male. 



Psoroptes equi. Two of the posteno 

 legs of mature female. 



instead of dentate nippers, and the palpi are soldered on each 

 side of them, so as to make them form a sort of tube. The jointed 

 or telescopic suckers or ambulacra, as they are called, as shown 

 above, also easily distinguish it The difference in the sexes is of a 

 similar nature to that in Sarcoptes. The above cuts show the 

 difference between the two posterior pairs of legs in the mature 

 male and female. There are other differences in the immature 

 stages. 



