Mites Injurioris to Domestic Animals. 91 



have been found on rabbits, but little is known about the structure 

 or habits of this mite. 



Some of the mites of the genus Laelaps, C. L. Koch, are parasitic 

 on rodents, moles, and other small mammals. One species 

 (L. echidninus, Berlese, fig. 71) is parasitic on the brown rat and, 

 like its host, is probably cosmopolitan ; another species (L. nuttalli, 

 Hirst) is common both on the black rat and brown rat in 

 tropical regions. The species of Haemogamasus, Berlese, suck the 



FIG. 76. 



Sternostomum rhynolethrum (p. 92). Female from below. 

 (After Berlese.) 



blood of various small mammals such as moles, field mice, etc. ; 

 and one species (H. oudemansi, Hirst) is found on the brown rat in 

 this country. 



Genus Ratllietia, Trouessart, 1902. 

 Raillietia auris, Leidy, 1872. 



(Figs 72-74.) 



In general appearance this mite resembles a Dermanyssus or 

 Liponyssus. Second leg of male very characteristic, being armed 



