ABYSSINIAN VINAOO. 
203 
wing-covers, so that no specific distinctions can be 
founded exclusively upon any one of these three 
circumstances. On the other hand, the two birds 
we have received from Senegal, although they agree 
in their colours with those figured on the 276th 
and 277th plate of Le Yaillant, differ most remark- 
ably from each other in the size and general struc- 
ture of their bills. Now, we do not remember a 
single instance in the whole circle of ornithology 
w’here such a variation takes place in the sexes of 
one species. To illustrate this difference more 
fully, we annex cuts 
of the bills of both ; 
in that to which we 
retain the old name 
of Abyssinica; the nos- 
trils are placed close to 
the base of the bill, so 
that some of the frontal 
feathers advance close 
to the aperture, the 
base also is narrow and compressed : in our Vinago 
nudirostns, on the contrary, the aperture is placed 
in the middle of the hill , half-way between the front 
and the tip, while the basal portion is broad and 
thick ; this structure is confirmed by two specimens, 
in a very perfect state of preservation, now before 
us, which precludes the supposition that the feathers 
have fallen off at the base of the bill. We shall 
now describe the colours and measurements of the 
first of these species. 
