SUBORDER MALLOPHAGA. 193 
has been generally accepted by English and American writers as the 
hologaster, this being due to the description and figure given by Denny, 
who does not seem to have seen the true hologaster, but described for 
it, according to Piaget, an immature specimen of the larger species since 
described as Goniocotes abdominalis Piaget. 
The hologaster is only about 1 mm. in length, whereas the abdominalis, 
or Denny’s hologaster, is about 3mm. In general form the species are 
somewhat similar, the hologaster being less constricted at the thorax 
and more regularly tapering to the end of the abdomen. The head is 
more nearly quadrate; the abdomen not so conspicuously marked, the 
incurved margins of the segments not extending so decidedly upon the 
disk and presenting the distinct lines seen as a border to the fasciz in 
abdominalis. 
LARGE CHICKEN LOUSE. 
(Goniocotes abdominalis Piaget; = G. gigas Taschenberg. ) 
This is probably fully as common as the preceding species. As 
already stated, it is the form which has been commonly 
referred to in English and American works as the Gonio- 
cotes hologaster, which doubtless accounts for its not 
having been described until quite recently. 
It is a large, conspicuous species, about 3 millimeters 
in length, quite broad, the head nearly circular in front 
and constricted behind, 
the thorax small, the 
abdomen widening to 
I near the end and termi- 
nating abruptly. The Fre. 113.—Gonio- 
head, thorax, and legs aes ag 
are yellowish, with dark 
margins and spots; the abdominal seg- 
ments bear lateral whitish fasciz bor- 
dered with black. 
It appears to be much Jess common 
than some other species of chicken lice, 
notably Menopon pallidum and Lipeu- 
rus variabilis. 
= & 
ele POSEN RES 
t as gece 
bene J 
KAT OSS 
(aps ES. 
PIGEON LOUSE. 
Fic.114.—Goniocotes compar—enlarged (au- 
fearh Winatintinn,) (Goniocotes compar Nitzsch.) 
A species which has been familiar for a long time and generally 
common, along with other lice, on domestic pigeons. It is a rather 
4653—No. 5 13 
