GAMASIDS. 



157 



Family GAMASIN^. 



The members of this family are either found on the ground in 

 damp places or parasitic on some animal or other; and subject to 

 the usual qualification of occasional exceptions, the palpi are fili- 

 form, that is, of nearly uniform thickness throughout; they usually 

 project forwards on each side of the mandibles, and have the ter- 

 minal articles bent downwards. The mandibles are chelate, that 

 is, provided with minute nippers. There are no eyes. The legs 

 are not ciliated, but adapted for motion on dry land. They have 

 seven joints, and there is a tendency in the second pair of legs in 

 some species to become larger and thicker than the others, often 

 with knobs or excrescences on different parts of them. The tarsi 

 have two claws, which emerge, as it were, from or alongside a kind 

 of frill or bag, which is called a caruncle, and which no doubt ful- 

 fils to some extent the office of a sucker. The accompanying 

 figures show some of the different forms this caruncle assumes. 



Claw and caruncle of 

 Gaiuasus tetragonoides. 



Claw and caruncle of 

 Dermanyssus avium. 



Claw find caruncle of 

 Sejus auris. 



In some species the skin is chitonous, like the covering of a 

 beetle, but not so hard ; and the colour is usually pale brown or 

 fawn. In certain species the skin is chitonous only in part, the 

 rest being soft, pliant, and colourless ; and in others it is entirely 

 soft, and naturally white or yellowish, but showing the colour of 



