ORDER PSEUDONEUROPTERA. 
SUBORDER MALLOPHAGA. 
This group embraces all the biting lice infesting birds and mammals. 
They are very distinct, indeed, from the preceding group, though fre- 
quently placed with them under such unnatural divisions as Anoplura, 
Pediculines, etc. 
The bodies are usually hard and horny and much flattened. They 
possess mandibulate mouth parts adapted to cutting and biting the 
hairs, feathers, epidermal scales, or excretions on the bodies of their 
hosts. They are said also to have a suctorial organ by means of which 
they may at times draw blood from the host animal. The mandibles 
are situated in most forms underneath the head and near the center, 
the clypeus projecting and forming the most anterior portion of the 
head. The labrum is present aud the maxillary palpi are prominent in 
a part of the order. The eyes when visible are located back of the 
antennae. The antennae are five-jointed except in Trichodectes. The 
thorax is generally narrow and frequently but two divisions are appar- 
ent. The legs are adapted to clasping (Philopteridce) or to running 
(Liotheidce), the tarsi in the first case being short and fitted for clasp- 
ing against the tibiae, and in the second case being long and provided 
with two claws well adapted to running. The members of the first 
division occur on both mammals and birds, those of the second, ex- 
cept Gyropus, are limited to birds. Wings are eutirely wanting and 
the abdomen contains nine or ten segments and is usually oval in shape. 
In life history this group agrees with the preceding. The eggs are 
glued to the hairs or feathers of the host animal and open with a cir- 
cular cap or lid at the free end. The larvae are less flattened, shorter 
in proportion, and without the hardened parts common to the adults 
covering a part or all of the surface. The length of life and rapidity 
of multiplication has not been determined for any species so far as we 
know, and the habits of the insects make any such determination a mat- 
ter of great difficulty. 
The effect of these upon the host animal may be less important than 
that of the suctorial lice, but judging from cases where serious results 
follow from the efforts of the animals to rid themselves, and from the 
known irritation due to the crawling of anything among hairs and 
feathers, it cannot be doubted that they cause much inconvenience to 
the creatures which become their involuntary supporters. 
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