202 INSECTS AFFECTING DOMESTIC ANIMALS. 
THE VARIABLE CHICKEN LOUSE.,. 
(Lipeurus variabilis Nitzsch. ) 
This species appears to have been recorded as early as 1668 by Redi, 
later by Frisch, unless these both refer to Menopon pallidum, and to 
have received a brief description by Linneus (Fauna Sue- 
cica, No. 1960) under the name of Pediculus caponis. The 
name by which it is now universally known, however, was 
given with description by Nitzsch in 1818 (Germar’s Mag., 
III, 292), While no very extensive literature seems to 
have accumulated in reference to this particular species, 
it is of course included in the many articles referring to 
poultry lice in general. It does not seem, however, to be 
so abundant as some of the other species infesting the 
common domestic fowl. 
It is about 2 mm. (one-twelfth of an inch) in length, the 
eee body elongated, of a whitish color, and smooth and shin- 
abilis—en- ing. The margins of the body are black; the head is large, 
PS ledg rounded on the anterior margin, and the whole appearance 
sufficiently distinct from any of the species infesting the 
chicken, so that, with the aid of the figure, there can be no difficulty in 
distinguishing it at a glance. Denny says: ‘Common on the domes- 
tic fowl, preferring the primary and secondary 
feathers of the wings, among the webs of which 
they move with great celerity.” 
THE WHITE SWAN LOUSE. 
(Ornithobius cygni Denny; O. bucephalus Giebel.) 
This Jarge and handsome species was quite 
certainly recognized by Redi and figured by him 
and has received frequent mention since. It is 
a& conspicuous species, and appears to occur in 
great abundance on different species of swans, 
so that it is readily obtained. It has been re- 
corded as occurring on the domestic and wild 
swan of the old world as well as the musicus 
and bewickii, and we have taken it in great 
abundance from the common swan of this coun- 
try, probably the Trumpeter Swan. 
The body in this species is whitish, but so rie. 125.—Ornithodius eygni— 
transparent that all the internal organs are Bae @uthors sae 
easily seen through the body walls. There are 
black points at the outer hind margins of about four of the abdominal 
segments, as shown in the figure, and the last segment in dusky or 
nearly black. It is 4 mm. long (one-sixth of an inch), and the body is 
