228* IXODID.E. GAMASID^. HTDRACHNID^. 



skins of animals whose blood they suck. They are usually of a 

 flattened, round, or oval form ; but they often acquire a very 

 large size by suction, and become distended like a blown bladder. 

 They are found in thick woods, abounding in brushwood, briars, 

 &c., and attaching themselves to plants with the two fore legs. 

 They fasten upon dogs, cows, horses, and other quadrupeds, and 

 even upon reptiles ; and they bury their suckers (which are 

 often furnished with minute recurved hooks, as in the Ixodes, 

 Fig. 561), so firmly in their skin, that they can hardly be detached 

 by force, the portion of skin to which they are attached coming 



FIG. 561. IXODES FIG. 562. a, HYDRACHNA GLOBULV8 ; 



PLUMBEUS, AND ITS b, magnified ; e, young larva ; d, pupa. 



BEAK, magnified. 



away with them. It is probably the young of a species of this 

 group, which is commonly known as the Harvest-Bug ; this is 

 very common in the autumn, upon grass or other herbage ; and 

 insinuates itself into the skin at the roots of the hair, producing 

 a very painful irritation. In this state it possesses only six legs. 

 The GAMASID^}, or Beetle-Mites, resemble the Ixodidce in 

 many respects, and like them are parasitic upon various animals ; 

 they are distinguished from the Ixodidae by their free, filiform 

 palpi, which do not form a sheath for the rostrum as in the 

 Ticks. They usually live in the nests of their victims, coming 

 forth from their hiding places during the night. One species is 

 common in bird-cages, where it often does serious injury to our 

 little feathered favourites. 



840. In the preceding families, consisting for the most part 

 of parasitic animals, the majority of the species are destitute of 

 eyes ; in the remainder of the typical Acarina these organs are 

 present. The HYDRACHNID^:, or Water-Mites, have the legs 



