VALE HETEROSTIGMATA—PROSTIGMATA =: Avil 
The curious Beetle-parasites attached to their victim by a 
thread belong to the genus Uropoda of- the Uropopinak. 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 
Trombidudae 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 yyg. 246. — Budella ae 
spiders. nicola, x about 50. 
(After Canestrini.) 
The minute active scarlet Mites of the 
genus Hupodes and its allies perhaps come within this family. 
Their legs are six-jointed. 
