156 THE ANIMAL KINGDOM. 



Aracknida, that is, they breathe by means of trachea and 

 spiracles, and not, as the higher order of spiders, by lungs, 

 or internal gills. They have eight legs, two long palpi 

 armed with claws ; the eyes are at the side of the thorax, 

 and the flat abdomen is jointed. 



ACARTJS GAMASUS, 



found abundantly on the Dung-beetle, which it infests. 

 This has a trifid labium, mandibles cheliform, denticulate, 

 the tarsi terminated by two claws, and an elegant pulvillus, 

 which make it worth mounting. 



Scottish peasants have a habit of examining the Dung- 

 beetles in the Spring, and observing the position of the 

 acari on their bodies : if the parasites are clustered near the 

 head, there will be a fine harvest, if towards the end of the 

 abdomen, a late one. 



TROMBIDIUM PHALANGII. 



A pretty little parasite, which attaches itself to the 

 Phalangium, or Harvest-spider. These spiders have small 

 oval bodies and very long legs, with two eyes on their backs, 

 and always run upon the ground ; we find these little scarlet 

 mites attached to their legs and bodies. 



TROMBIDIUM ATJTTJMNALE. 

 (Harvest-bug.) 



This troublesome little parasite is found in corn-fields in 

 August, and burrows in the skin, causing much painful 

 irritation. The best way of catching it is to tie pocket- 

 handkerchiefs round the legs, and walk through a stubble- 

 field, when we are nearly certain of finding specimens 

 enough in the folds of the handkerchief. They are mounted 

 in balsam. 



In all the Trombidia, observe the form of the chelicerse, 

 with their moveable claw, and the palpi, which have a 

 singular appendage or finger beneath each extremity, 

 which distinguishes them from the common Acari, and show 

 their relationship to the pretty scarlet Water-mites, the 

 Hydraclina., 



