47 
gin. They are hardly as conspicuous as in sealaris and apparently 
rather longer and more conspicuous than in jjilo.su* * 
Piaget describes two varieties of this species, one from the BurcheH's 
Zebra (Equus burclielli) which he calls var. ocellata on account of a 
series of eye-like uncolored spots on the abdomen, and the other from 
the small horses of Java, var. tarsata, which has the second joint of the 
tarsi particularly developed and which he mentions as in some resp 
approaching pilosus. 
The habits of this species are well known and have received mention 
for many years. They seem to accumulate more particularly upon colts 
or horses in pasture, but their presence becomes most manifest in the 
latter part of the winter, when they may become so numerous as to cause 
great irritation to the animals infested. They occupy more particularly 
the region of the neck, and also accumulate around the base of the tail 
and between the legs, and the animals will frequently rub bare places in 
these regious in their attempts to rid themselves from the irritation. 
It is unnecessary to give any special notice regarding treatment, as 
they must be attacked on the same plan as other species. 
Even if it proves that this species does not ordinarily infest the mule 
or donkey it would be policy not to allow these animals, if infested, to 
associate with horses, as we have no assurance as yet that they can not 
thrive on any of the members of the equine family. 
BITING LICE OF CATTLE. 
(Trichodectes scalaris Nitzsch.) 
This species, which is a very abundant one upon cattle and occurs 
the world over, appears to have been first tech- 
nically described by Linnaeus (System. Naturae, 
Til, p. 1017, Xo. 9,) under the name of Pediculu.s 
bovis, and evidently the same species is referred 
to under the name of PedicuJus tauri (Fauna 
Suecica, 1946). Notwithstanding these descrip- 
tions, both of which were under a different genus 
from that in which it is now placed, the species 
was again described by Mtzsch (Germar's Mag- 
azine, 111,296) under the name of Trichodectes sca- 
Jaris. and it has been known by this name in all 
of the numerous writings subsequent to this 
description. It has been treated by all writers 
upon the parasites of animals and is one of the 
best known species of parasitic insects. The 
effects upon the cattle infested are often quite 
serious on account of their great number, but 
.i .1, .... 36. — Trichodectel scalaris. 
they are apparently less injurious than the suc- 
torial species which infest cattle. This injury depends, of coarse, upon 
* The Lair liue in the figure is about one-ht'th longer than it should he 
