CHEYLETUS. 285 



CASE It is unnecessary to dwell upon or describe this most remarkable 

 mite. The beautifully-executed woodcuts of it by Mr. Whymper, 

 which are scarcely less remarkable in their way than the mites 

 themselves, will give the reader a fair idea of it. 



It is more common than the preceding, and found in the same 

 places and associated with it. As both have been found in 

 France and Germany, they may possibly also be found in the 

 southern parts of this country, if properly sought for. 



Genus Cheyletus {Latr.). 

 A very remarkable type ; distinguished by enormous, rapacious 

 palpi. It is unquestionably carnivorous, its palpi being contrived 

 for holding its prey, while its rostrum is sharp, and well suited 

 for plunging into the body of its victim, whose juices it is to suck 

 up. Apart from the formidable palpi, its general appearance is 

 that of a Tyroglyphus. Its palpi, although so differently shaped, 

 are composed of three joints, like those both of the Tyroglyphid^ 

 and the Sarcoptidae, but thick and broad as in the latter, instead 

 of small and inconspicuous as in the former. It has a fleshy, 

 semi-transparent body, like the Tyroglyphidse, but on examination 

 under a powerful glass, it is seen to be not smooth Hke them, but 

 striated, as the Sarcoptid^ are, only much more finely than them. 

 The legs are five-jointed as in both, and the tarsus has two claws, 

 with a divided smaller claw between them, looking like two. The 

 transparent tarsal sucker, too, is not so visible as in Tyro- 

 glyphus, and it wants the conspicuous separate suckers of the 

 Sarcoptidai. One of its most remarkable features, is the posses- 

 sion of a tracheal breathing apparatus on a plan, which forms a 

 double anastomosing system through the body, and communicates 

 with the air by a joint median stigmatic opening at the symphysis 

 of the two jaws, and by another lateral one on each side at their 

 base, on the outer side, the air probably entering by the middle 

 opening and taking its exit by the lateral ones. This, as well as 

 the whole of the anatomy of Cheyletus and its allies, is beautifully 



