NOTES ON THE STRUCTURE OP BIRDS. 
ON THE FORM OF 
THE POSTERIOR MARGIN OF THE STERNUM 
OF THE 
VULTURID.E. 
✓ 
By T. C. EYTON, Esq., F.L.S., &c. 
Mr. Gray, in his excellent and most useful work, “ The Genera 
of Birds,” divides the Vulturidm into the following genera:— 
Gypcetos , Neophron , Sarcoramphus , Cathartes, Vultur , Otogyps, 
Gyps , and Gypohuraoc , excluding Serpentarius, which he classes 
with Circus , hut which must he again restored to the Vulturidce , 
the whole skeleton being that of a true vulture. Of the above nine 
genera, I have obtained the skeletons or made drawings of those 
of seven. On examining the accompanying plate, the first six 
appear to resolve themselves into a consecutive series, thus 4, 6, 
5, 3, 1, 2. No. 7 appears at first sight not to belong to the 
series, but upon comparing it with No. 2, we shall find some points 
of resemblance. 
In figure 2, representing the posterior margin of the sternum 
of Cathartes aura , the liyposternal portion is elongated laterally ; 
the drawing was taken from the skeleton of .a young bird, and it 
is probable that this process would be more developed in an older 
specimen. The posterior part of the entosternal portion is also 
elongated ; not so much so, it is true, as in Serpentarius , figure 7, 
but more so than in the other genera of vultures. Serpentarius 
differs however from Cathartes , in not having any orifices on each 
side of the sternum, but this we find also to be the case in Sar- 
coramphus, figure 4. I have given, for the sake of comparison, 
outlines of four other forms of the posterior margins of the sternum 
in the order Raptores , viz. — Aquila chrysactos , figure 8 ; Circus 
ceruginosus, figure 9 ; Nyctia nivea, figure 10 ; and Polyhorus 
hraziliensis, figure 11 ; to none of these, with the exception of 
the last, does Serpentarius present the least resemblance ; the 
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