LICE AFFECTING DOMESTIC ANIMALS. 199 
’'ediciilns eiirysternus, in 1818 (Germar’s Mag., vol. Ill, p. 305), 
nd has received mention in every important treatise on 
arasites since that date, as well as innumerable notices under 
le head of animal parasites, cattle lice, etc. As with other 
Decies, the disease produced has been termed phthiriasis, and 
s treated by Kollar and other writers it has been recognized 
5 a most serious pest and numerous remedies tried for its 
ippression. 
Since it has been very generally confused with the follow- 
1 g species we shall give more particular description and show 
5 clearly as possible how to distinguish them. The following 
uotation from Mr. C. W. Tenney (in Iowa Homestead for 
mgust 18, 1882) will show that this difference is not without 
iterest or value as viewed by a practical breeder : “ Then 
lere is a blue slate-colored louse and a larger one of the same 
Dior that vary somewhat in their habits, and the last men- 
oned is the hardest to dislodge.” Evidently it is the species 
nder discussion to which Mr. Tenney refers as the “larger 
tie.” It infests particularly the neck and shoulders, and these 
arts are frequently worn bare by the efforts of the animal 
) rid itself of the irritation produced by these unwelcome 
isitors. Still, some cattlemen say that these parasites are of 
□ consequence, and that they never pay any attention to 
lem. 
The full-grown females are about one-eighth to one-fifth of 
1 inch long, and fully half that in width, while the males are 
little smaller and proportionately a little narrower. Aside 
'om the difference in size the sexes differ very decidedly in 
le markings and structural features on the under side of the 
□dy. The males have a broad black stripe running forward 
•om the end of the body to near the middle of the abdomen, 
3 shown in Fig. 1 c (Plate I). 
The females have no indication of this stripe, but the black 
roken band of the upper side of the terminal segment extends 
ightly around on the under side. The most important char¬ 
ter, however, is the presence of two little brush-like organs 
n the next to the last segment, as shown in Fig. 1 d (Plate I). 
The head is bluntly rounded in front, nearly as broad as 
