HETEROSTIGMATA PROSTIGMATA 



471 



The curious Beetle -parasites attached to their victim by a 

 thread belong to the genus Uropoda of the UROPODINAE. The 

 connecting filament, which the Mite can sever at will, for a long 

 time puzzled observers. It was variously construed as a silken 

 cord of attachment, and as a sort of umbilical cord, through 

 which the Mite drew nourishment from the Beetle. On more 

 careful investigation it proved to be connected with the anus of 

 the Mite, and to consist of its consolidated excrement. 



The DERMANYSSINAE are all parasitic on warm-blooded animals, 

 principally birds and bats. Dermanyssus avium is the common 

 parasite infesting fowls and cage-birds. 



Sub-Order 4. Heterostigmata. 



Fam. Tarsonemidae. This is the sole family of the sub- 

 order. It comprises a number of minute vegetable-feeding Mites 

 which have been little studied, though they are probably the 

 cause of considerable injury to the leaves and buds of plants. 



Sub-Order 5. Prostigmata. 



In these Mites the stigmata are situated anteriorly, in the 

 rostrum or the thorax. In the Water-mites the tracheae have 

 atrophied, but these creatures are clearly 

 Trombidiidae which have taken to an 

 aquatic life. 



Fam. 1. Bdellidae. The Bdellidae are 

 sometimes known as the " Snouted Mites " 

 on account of the very prominent forwardly- 

 directed " capitulum " or false head. They 

 have chelate chelicerae and tactile palps, 

 which are often " elbowed," like the antennae 

 of weevils. Eyes may be present or absent. 

 They are usually of a bright red colour, 

 and are free-living and predaceous, though 

 in their larval stages they may often be 

 found attached to the limbs of insects and p 1G> 246. Kddi ///- 

 spiders. 



The minute active scarlet Mites of the 

 genus Eupodes and its allies perhaps come within this family. 

 Their legs are six-jointed. 



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x 



(After Canestrun.) 



