46 
Fig. 34. —Trichodectes 
pilosus. (After Piaget.) 
which has been widely used to designate the biting lice of the members 
of the horse family. The original reference dates back considerably 
more than a century, and doubtless the insect was familiar many cen- 
turies before that, as the horse and ass have been too familiar as domes- 
tic animals to allow of the parasites common to them escaping entirely 
the notice of man. 
According to Piaget this occurs upon both the ass and the horse, 
while the following species he has found only on the horse. 
We have not been fortunate enough to secure examples of this form, 
though we have the other in great abundance, so we 
are compelled in describing to depend upon the excel- 
lent description and figures of Piaget, the latter being 
reproduced here for comparison. The head in this 
form is shorter and less rounded iu front, that of the 
male being still less rounded than the female, while 
the abdomen is more slender and tapering. The trans- 
verse bands are also represented as less conspicuous. 
Perhaps the most striking point, however, is the posi- 
tion of the antennae, which stand well forward on the 
head, so that the front border of the head and base of 
the antenna are nearly in line. 
The habits of the species and the remedies applica- 
ble to it are naturally identical with those of the other related species. 
{Trichodectes parumpilosus Piaget.) 
While it does not seem possible that all the writers previous to Denny 
should have overlooked this form, which appears to be the more com- 
mon one, at least on the horse, it may be true that 
Denny was the first to give it a thorough ^descrip- 
tion and careful drawing. He speaks of it as com- 
mon on the horse and ass, but Piaget says he has 
never found it on the ass and there is of course a 
possibility that Denny did not distinguish between 
this and the preceding species. 
In this species the head is decidedly rounded in 
front, the antennae inserted well back, so that the 
head forms a full semicircle in front of the base of 
the antennae. The abdomen is more slender and 
tapering than in scalaris, but less so th&nin pilosas, 
as shown in Piaget's figures. The color is much 
the same as in the allied species, the head, thorax, 
and legs being a bright reddish brown or chestnut 
and the abdomen of a dusky yellowish color, with 
about eight transverse dusky bands occupying the 
central or anterior portions of the segments and 
extending from the middle liue a little more than half way to the mar 
Fig. 35.— Trichodectes parum- 
pilosus. (Original.) 
