SUBORDER MALLOPHAGA. 207 
still it was described in detail under the name given above. Denny’s 
reference to it would indicate it as rare in England. Itis of rather rare 
occurrence, which may be considered as fortunate, for, if abundant, it 
would be rather difficult to contend with on account of the long wool 
of the host. 
It has been fairly plentiful at Ames on sheep which came originally 
from Canada, and proved quite troublesome. Pyrethrum proved most 
useful in the long wool in winter. 
The name indicates its characteristic feature, namely, the rounded 
head. The color agrees closely with the related species. 
Where it occurs it will be the best plan to pay close attention to 
destroying them at the time of clipping the sheep even if they are but 
few in number, as at any other time the labor of making thorough 
applications for them is greatly increased. 
THE BiTrine LIcE oF HORSES, MULES, ASSES, ETC. 
( Trichodectes equi auct.) 
The original reference by Linnzeus to the lice of horses and asses 
under the name of Pediculus equi most certainly refers to the common 
Trichodectes infesting these animals, but Piaget has reached the conclu- 
sion that this reference is to the form subsequently described by Giebel 
as Trichodectes pilosus, and that the form described by Denny as equi, 
and which has since almost universally been treated 
as the Linnzan species, was in reality a different 
insect from that described by Linnzus under 
the same name. He therefore describes this 
form under the name of parumpilosus. lt is cer- 
tainly somewhat confusing to be obliged to drop 
the familiar designation for so common a species, 
and were it not that this conclusion has been reached 
by one who is probably the highest living authority 
regarding these insects we should hesitate to intro- 
duce the change. The figures given by Piaget, how- <-¥\\\ 
ever, leave no question that there is a decided differ. iapeesk 
ence between pilosus and parumpilosus, and it is Fre. 132.— Trichodectes 
equally certain that our common species belongs to Pash es mn 
the latter form; so, if there is no question as to 
Linneus having the form pilosus in hand, we certainly have no right 
on technical grounds to apply the term equi to our common form. We 
will therefore introduce descriptions and comparisons of the two forms 
and adopt, for the present at least, and on the authority of Piaget, the 
hames given in his Les Pédiculives. 
ie i ea 
