NO. 3558 MALLOPHAGA—ELBEL 4] 
short seta may be present on margins of abdominal tergites II-VI in 
Chapinia. Male terminal abdominal sternites VIII and IX may be 
fused in Bucerophagus and Bucerocolpocephalum with a complete 
division from abdominal sternite VII, but abdominal sternites VIII 
and IX are fused in Chapinia with a partial division only from ab- 
dominal sternite VII. Male genitalia of Bucerophagus are longer than 
in Bucerocolpocephalum; parameres are branched anteriorly in Bucero- 
phagus but are slender or expanded anteriorly in Chapinia. Lateral 
processes arising from the ventral sclerite between the female vulva 
and anus have long stout setae and strong spines in Bucerophagus and 
Bucerocolpocephalum but only long stout setae in Chapinia. The 
female anal fringe prominent in Bucerophagus and Chapinia is weak 
in Bucerocolpocephalum. 
The male genitalia and details of the male and female terminal 
abdominal segments are the best characters for separating species of 
Bucerophagus. Other characters useful in species separation are: 
The shape of the metasternal plate and the number of setae present; 
the presence or absence of brushes of normal setae on the venter of 
the third femora and posterolateral margins of abdominal sternites 
IV and V; the number present or absent of short setae on each lateral 
margin of abdominal tergites III-VIII between the spiracle and 
postspiracular seta; the total number of setae on each of abdominal 
sternites I and IJ. The number and length of setae on the lateral 
margins of the gular region are too variable to be of much use in 
separating species. 
Kichler (1947) believed that the lack of brushes, the rounded pro- 
jected lobe on the posterior end of the male abdomen, the specific male 
genital apparatus, and the female anal ring of setae were enough to 
place Menopon forcipatum Nitzsch in a separate genus. Hopkins and 
Clay (1952) correctly placed M. forcipatum in the genus Bucerophagus. 
Since there are several characters separating B. forcipatus from the 
complex B. productus and B. africanus, it is believed here that the 
relationship can be shown best by species-groups. 
Hosts: Species of Bucerophagus have been found only on the genera 
Buceros, Rhinoplax, and Bucorvus of the avian family Bucerotidae. 
The forcipatus Species-Group 
As illustrated in figures 66, 67. Differing from the productus 
species-group in the following combination of characters: Head 
width 1% to 1% times that of length; metanotum with two short setae 
on each lateral margin and without setae on anterior margin; meta- 
sternal plate with less than 14 setae; venter of third femora and 
abdominal sternites IV and V without brushes; each lateral margin of 
abdominal tergites II-VIII without short setae between the spiracle 
