13 
yield to the treatment used for the other species, though the long hair 
would make some of them more difficult of application. On this account 
fumigation where possible would seem to be most practicable. 
THE SHORT-NOSED OX-LOUSE. 
(Hcematopinus eurysternus, Nitzsch.] 
This is the species that has probably been familiar from early time 
as the louse infestiug cattle, though since this species aud the following 
one have been generally confused, it is impossible to say which has 
been most common. It was first accurately described by Nitzsch under 
the name of Pedicidus eurysternus,m 1818 (Germar's Mag., vol. m, p. 305), 
and has received mention in every important treatise on parasites since 
that date, as well as innumerable notices under the head of animal 
parasites, cattle lice, etc. As with other species, the disease produced 
has been termed phthiriasis, and as treated by Kollar and other writers 
it has been recognized as a most serious pest and numerous remedies 
tried for its suppression. 
Since it has been very generally confused with the following species 
we shall give more particular description and show as clearly as possi- 
ble how to distingush them. The following quotation from Mr. 0. W. 
Tenney (in Iowa Homestead for August 18, 1882; will show that this 
difference is not without interest or value as viewed by a practical 
breeder: " Then there is a blue slate-colored louse and a larger one of 
the same color that vary somewhat in their habits, and the last-men- 
tioned is the hardest to dislodge." Evidently it is the species under 
discussion to which Mr. Tenney refers as the "larger one." It infests 
particularly the neck and shoulders, and these parts are frequently 
worn bare by the efforts of the animal to rid itself of the irritation pro- 
duced by these unwelcome visitors. Still, some cattlemen say that 
these parasites are of no consequence, and that they never pay any 
attention to them. 
The full-grown females are about one-eighth to one-fifth of an inch 
long, and fully half that in width, while the males are a little smaller 
and proportionately a little narrower. Aside from the difference in 
size the sexes differ very decidedly in the markings and structural fea- 
tures upon the under side of the body. The males have a broad black 
stripe running forward from the end of the body to near the middle of 
the abdomen, as shown in Fig. 6c. 
The females have no indications of this stripe, but the black broken 
band of the upper side of the terminal segment extends slightly 
around on the under side. The most important character, however, is 
the presence of two little brush-like organs on the next to the last » _ 
ment, as shown in Fig. 6d. 
The head is bluntly rounded in front, nearly as broad as long, and 
with the antenna? situated at the sides midway from the posterior to the 
