82 PYROMELANA AFRA 
Lieut. Thierry. In the Niger district specimens have been 
collected by Dr. Hartert at Loko, by Forbes at Hgga, and 
by the late Capt. Thompson at Iddah. This latter specimen 
is probably the one in the British Museum, and the locality, 
Fernando. Po, incorrect, so I have not entered within the 
range of this species either Fernando Po or the Quanza 
River, the latter locality resting on a specimen labelled 
“ Quanza (Whiteley),’’ contained in a small collection procured 
from Mr. Whiteley, for the Lisbon Museum, in 1876. It is also 
recorded by Dr. Reichenow (Vég. Afr. iii. p. 117) from ‘‘ Benguela 
II. (Mocquerys).” My objection to these three latter-named 
localities for the species is that it has not otherwise been 
mentioned from south of the Niger River. 
The group to which I have applied the name of Yellow- 
crowned Bishop-birds comprises four species. The present 
one is well marked; the other three are scarcely distinguishable 
at first sight, the only constant character being their size. The 
smallest is P. ladoensis, with a wing measuring about 2°2 inches 
inhabiting North-east Africa to the north of the Equator; 
it is sometimes, but not always, easily recognisable by having 
the sides of the chest strongly marked with yellow, which 
is never met with in P. afra or P. stricta, although all the 
forms have a yellow patch on the sides of the crop. That the 
yellow on the sides of the chest in P. ladoensis is not a constant 
character is proved by a series of five full plumaged males 
obtained by Emin at Lado in June and July; in one of these 
the sides of the chest are uniform black, as in P. taha and 
P. stricta, while in two others the flanks are almost entirely 
yellow, as in the type of P. ladoensis, and the other two are 
intermediate in colouring. In P. taha and P. stricta there is 
never any trace of yellow on the sides of the chest beyond 
the crop-patch; in the former the wing measurement is 2°4 
and in the latter 2°7 inches, 
