SHUFELDT.] OSTEOLOGY OF THE CATHARTIDA. T71 
For Cathartes aura we present the reader with the principal variations 
that we have found to exist, carefully selected from various sources and 
collections. 
Mr. T. C. Eyton, in his Osteologia Avium (London, 1867), in a half view 
of the sternum of this Vul- 
ture, found it as in spec. No. 
692, here given, only the fora- 
men was a little larger (Pate 
I, fig. 2, of HEyton’s work). 
We, however, read in the text 
of this book, page 19-20 (C. 
aura), “Sternum in general 
shape similar to Sarcorham- 
phus, but with two large fis- 
sures on the posterior margin 
next the keel, and two fissures 
exterior to them; the remain- 
ing portions of the skeleton Cathartes aura, No. 6897 of the Smithsonian collection. 
are very similar except in measurements.” Now here is a writer that 
actually contradicts his own drawings by the statement he makes in the 
text,and we ean only believe that 
Mr. Eyton could have been Jed 
into such an apparent mistake by 
having several specimens of the 
sternum of this bird at his dis- 
posal, availing himself of one for 
his plate and another for his 
description, perhaps at a later 
date. ; 
This gentleman found his spe- 
cimen of “Cathartes niger,” as we 
see from an examination of the 
plate presented, with a large Qathartes aura, No. 3102 of the collection of the Smith. 
elliptical foramen on either side; ECR Doh 
while, on the other hand, in a specimen we received from Florida, and 
shown in the cut, the arrangement is seen to be entirely different. 
Gyparchus papa apparently shares 
the same fate that C. aura does in 
this respect, for in one Ecuador 
specimen (Plate XV, fig. 105) the 
xiphoidal margin is encroached 
upon on either side of the keel by 
a broad and rather deep notch, 
each being of the same size, while, 
in a specimen of this Vulture from 
Mazatlan, this is the condition of 
the bone on the right side of the 
keel, the left having an additional 
small notch ae the outer side of the 
large one. Mr. Eyton found his as ; : 
in our Ecuador bird, and describes ‘, RPA aRacec ahi rasttu econ), roraplant 
it as having “two large open fissures,” op. cit. 
Referring to these matters, Professor Owen says: 
In diurnal Raptores the sternum is a large elongate parallelogram convex outwardly, 
both transversely and longitudinally. The manubrium is short and trihedral; the 
