PARASITES OF ANIMALS. 45 
D. Gallopavonis infests the turkey. The body is marked 
by peculiar, delicate, transverse strie, and with numerous 
small circular impressions on the back. 
D. avium torments small cage birds, like the canary. It 
often takes refuge in cracks about the perches, which should 
therefore be kept clean. 
ARGAS Latreille. 
This genus includes the famous Argas Persicus, which 
infests old dwellings in Persia, especially at Miana, and is 
said to be so poisonous that its bite produces convulsions and 
speedy death ; or even its juices, if crushed upon the skin, 
may produce the same results. 
These are larger than most of the mites, and somewhat 
resemble the ticks. The body is broad-oval or roundish. 
The upper side of the head so projects as to conceal the mouth 
parts. The jaws are suctorial. The lower side of the body 
is granulous, not scaly, and covered by a single piece. 
Argas reflexus Latreille lives upon pigeons and sucks their 
blood. It especially infests the young, upon which there are 
sometimes great numbers. The body is marked with curious 
tortuous grooves and pits. The color is yellowish, but when 
filled with blood violaceous. 
IXODES Latreille. (Ticks). . 
These are the largest of the Acarians, and all are parasitic, 
chiefly upon quadrupeds and reptiles, but sometimes on birds. 
The body is broad-oval or round, and When not swollen with 
blood is flatish, and the integumentisfirmandtough. Their 
mandibles (Figure 43,b,) are covered with teeth and have ter- 
minal hooks ; their maxille are small, not reaching beyond the 
beak, but bear a peculiar organ called the glossoid (Figure 
43,a,) also covered with hook-like teeth. The legs are slender 
and have two claws, and in the young have pads or suckers 
(d). The young are six-legged (Figure 42). The ovarial 
opening is near the mouth, between the first pair of legs. 
These parasites, when young, cling in large clusters to the 
tips of leaves and twigs of herbs and shrubs, with part of 
their six slender legs extended. When brushed by a passing 
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