1864.] MR. G. R. GRAY ON A NEW PRIONOPS. 45 
Two other species of this family are contained in the Expedition’s 
collection, viz. Turacus porphyreolophus and Coliphimus concolor. 
The former differs in having a larger space of rich golden green on 
the sides of the head, while the rufous tint is entirely wanting on 
the breast. The second species also offers some slight variations, 
viz. the crest and throat are of a lighter colour. Thus both species 
differ in some respects from the specimens obtained in the Cape 
Colony; but, I suppose, they will come within the category of 
local varieties. 
3. On a New Species or Prionors. By G. R. Gray. 
I beg to lay before the Meeting the description of a new species 
of Prionops, which has been obtained during the Zambesi expedition. 
PRIONOPS TRICOLOR. 
Black ; back, ramp, wing-coverts, and tertials purplish grey ; quills 
fuscous black, from the second to the tenth quills crossed interiorly 
with a white oblique band ; vent, under tail-coverts, and tips of the 
tail-feathers white; on the latter the white decreases in width from 
the outer to the central feathers, where it exhibits only a small spot 
on each feather. 
The frontal plumes covering the nostrils are short, turned upwards, 
and slightly curved backwards in front of the eyes, like those of the 
Prionops talacoma, which latter species, with the new one, were sent 
in the first series of birds as from Tette. 
The eyes are surrounded by serrated fleshy rings. The bill and 
feet red; the former is tipped with yellow. 
Length 7" 6"; wings 5". 
This new species is allied to Prionops retzii, but it is without the 
white rump, and the tips of the tail-feathers are white on both webs. 
There are six species now known of the genus Prionops; they 
consist of 
. plumatus, Shaw. 
. poliocephalus, Stanley. 
. concinnatus, Sundev. 
. talacoma, A. Smith. 
. retzii, Wahlb. 
. tricolor, G. R. Gr. 
The allied genus, Sigmodus, contains three species, viz. 
=] jh” iea=)ay~ [og] 
S. caniceps, Temm. 
S. rufiventris, Bp. 
S. scopifrons, Peters. 
All the species of these two genera are confined to the continent 
of Africa. 
