Mites Injurious to Domestic Animals. 93 



cryptorhynchum, Berlese and Trouessart) is parasitic on the com- 

 mon sparrow. An allied mite (Ptilonyssus nudus, Berlese and 

 Trouessart) occurs in the nasal cavities of the common sparrow, 

 whilst others (Rhinonyssus, etc.) are parasitic in various birds both 

 in Europe and elsewhere. 



FAMILY HOLOTHYRIDAE. 



The Holothyridae are rather large reddish mites with the upper 

 surface of the body convex and shining, the integument being hard. 



According to some recent authors these mites should be regarded 

 as forming a distinct family, but in general appearance, position 

 of the stigmata, etc., they are very like Gamasid mites, and are 

 regarded by some authors as being closely allied to that family. 



Genus Holothyrus, Gervais, 1842. 



(Fig. 77.) 



Holothyrus coccinella, Gervais, 1842. 



This species lives in the Island of Mauritius. It secretes an 

 irritant poison, and is sometimes swallowed by ducks and geese, 

 causing their death ; for this reason it is called " touille canard " by 

 the inhabitants. Children have suffered ill effects through putting 

 the mite in their mouths, or from meddling with it and afterwards 

 touching the mouth with the fingers. 



