274 INSECTS AFFECTING DOMESTIC ANIMALS 
THE SMOOTH SARCOPTES. 
(Sarcoptes levis Railliet. ) 
This species, described by Railliet in 1885, is represented by severak 
varieties that live in the feather bulbs of birds, notably the pigeon and 
hen. It has not been observed as yet in America, but it is quite likely 
that it may be found to occur here. 
Family DEMODECID 2. 
This family includes only one genus, the description of which will 
indicate the family characters. 
THE FOLLICLE MITE. | 
(Demodex folliculorum Simon.) 
The follicle mites are rather degenerate worm-like forms that occur 
in the hair follicles of different animals, the variety occurring on man 
(hominis), producing the little specks or blackheads so frequent on the 
face, and which are said to be almost uni- 
versaliy present, though it is seldom they 
cause any special irritation. The variety 
occurring on dogs (Canis), produces a se- 
rious disease, aS does also the one on hogs 
(Swis). In both these animals the affected 
parts are the face and nose and occasion- 
ally larger tracts of the body. 
The variety on cattle affects the body at 
large and has a somewhat different inter- 
est, aS it is recorded as damaging the hides 
for market. A record of its occurrence in 
this manner is given by Walter Faxon and 
also by Dr. C. W. Stiles. 
The mites evidently undergo all stages 
2 = a ac a a J ees var. of development in the follicles, but doubt- 
ominis: a, mite greatly enlarged; 2 3s 
b, mites in hair follicle and seba- less migrate over the surface of the skin 
ee ag es (copied from when mature and before laying eggs. 
The use of dips and washes would seem 
to be the only sure treatment for domestic animals, and if it is thought 
necessary a Similar mode could be adopted for man. 
Order LINGUATULINA. 
This group, which includes a few species of remarkably modified 
Arachnids, may be recognized by the worm-like footless condition 
of the adult, two pairs of hooks at the sides of the mouth, and the 
may 
