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The order may easily be separated into two families upon characters 
a part of which have already been mentioned, namely, the structure of 
the mouth parts and the feet. The latter, which is the most easily ob- 
served, can easily be told from the mode of locomotion, the members of 
the first group being incapable of rapid movement but well adapted to 
clinging to the hairs or feathers, the latter running freeiy and swiftly 
but having less power to clasp. 
FAMILY PHILOPTERIDE. 
Infesting horses, cattle, sheep, dogs, cats, chickens, turkeys, pigeons, 
ducks, ete. 
The members of this family have the mouth parts on the under side 
of the head. Mandibles strong; maxille wanting; tarsi short, of one 
or two joints, the claw meeting a tooth at the apex of the tibia; meso- 
thorax apparently wanting; abdomen having nine segments. 
The group is a large one, the species being so numerous that scarcely 
a bird but harbors one, and sometimes several, species of this family. 
The genera are, for the most part, easily separated ; Docophorus, by 
the presence of a movable appendage (trabecula) in frout of the anten- 
ne; Nirmus, by the presence of an immovable tooth in front of the 
antenn and the generally entire terminal segment of the abdomen of 
the female. Goniocotes and Goniodes are robust forms, usually with 
large heads strongly curved in front; they differ by the former hav- 
ing simple antenne in both sexes, while in the latter they are modified 
in the male. The former are also usually much the smaller. In Lipeu- 
rus the body is generally long and slender, the antenne of the males 
large and often with a complicated structure, while the terminal seg- 
ment of the female is bilobed. The species of Ornithobius Are white or 
transparent and especially characterized by having sbarp curved appen- 
dages meeting in front of the clypeus. Trichodectes is at once known 
by the three-jointed antenne. Other genera of the family do not contain 
species infesting domestic animals, and hence need not be noticed here. 
LOUSE OF DUCKS AND GEESE. 
(Docophorus icterodes Nitzsch.) 
This species has been recorded from so many different members of 
the order of birds containing the ducks and geese that it may be con- 
sidered as common to the order. It was described by Nitzsch in 1818 
and has been mentioned by most writers on parasites since that time. 
It is about 1 millimetre in length, and has the head and thorax of 
a bright reddish color wih darker bands. The abdomen is white in 
the center, with broad, dark reddish, horny bands at the sides, with a 
darker spot at the margin. 
