No. .ll.O] 



ECTOPARASITES OF MAMMALS 



271 



host-list, representatives of thirteen families, summing 

 about sixty species, being listed. Both Mallophaga and 

 Anoplura infest the rodents, but certain families are 

 parasitized almost or quite exclusively by Anoplura, 

 while Mallophaga are the only parasites of others. 



The Sciuridae (squirrels and spermophiles), for ex- 

 ample, with a dozen host species, are parasitized by a 

 dozen species of Anoplura with only a single Mallo- 

 phagan record; and a single record under such circum- 

 stances is always suspect. There is little commonness of 

 parasite species to two or more host species in this 

 family. Osborn's Polyplax Montana is recorded from 

 the eastern and western North American gray squirrels, 

 and his P. suturalis has been taken from two Spermo- 

 phile species, both, however, of the same general range. 

 The well-differentiated parasite genus Acanthopinus is 

 represented by one species from the common Old AVorld 

 squirrel, Sciurus vulgaris, and another from the eastern 

 gray squirrel of North America. These species, though 

 close together, really seem to be different. In addition I 

 have just found the Acanthopinus species of the eastern 

 gray squirrel on Douglas's squirrel in California, and 

 another (new) species on a California chipmunk. The 

 only Mallophagan species recorded from a Sciurid is 

 Gyropus turbinatus from the marmot, Arctomys mar- 

 motta, of the mountains of southern Europe. 



From the beaver (family Castoridae) a characteristic 

 Mallophagan species, Trichodectes cast oris, has been 

 taken in America. The beaver, it may be noted, is the 

 host of the only beetle {Platypsylla castoris) that has 

 become a specialized permanent ectoparasite, passing its 

 whole life on the body of its host. 



The Old World dormouse (family Gliridae or Myoxida?) 

 harbors a sucking louse, Polyplax pleurophaa. 



The large family Muridje, including the rats, mice, 

 voles and lemmings, is represented by twenty host species 

 well scattered over the world. There are twenty-two 

 Anopluran species and two Mallophagan species in the 

 parasite list for the group. Both of these Mallophagan 



