OSTEOLOGY OF BIRDS 39 



As a good instance of it we may. select as illustration various 

 sterna and descriptions of sterna of Cathartes a. septen- 

 trional i s . 



In the xiphoidal extremity of the sternum of this vulture, there 

 is an inner notch and an outer foramen upon the left side, and 

 two notches upon the right, the outer one of which is almost a 

 foramen. Now, in a specimen in the United States Army Medical 

 Museum, the sternum is singly notched upon either side, and no 

 foramina at all. Specimen no. 6897 of the Smithsonian Collections 

 is similarly notched, but has an outer foramen on the left side and 

 two of them on the right. No. 692 of the same collection is also 

 similarly notched and has in addition a foramen only on the right 

 side external to the notch. 1 



Mr T. C. Eyton, in his Osteologia Avium [London, 1867], in a 

 half view of the sternum of Cathartes a . septen- 

 trional i s , found it as in specimen 692 just referred to above, 

 only the foramen was somewhat larger [pi. 1, fig. 2]. We, how- 

 ever, read in the text of his work [p. 19, 20] " Sternum in general 

 shape similar to Sarcorhamphus, but with two large fissures on the 

 posterior margin next the keel, and two> fissures exterior to them ; 

 the remaining portions of the skeleton are very similar except in 

 measurement." 



Now here is a writer who actually contradicts his own drawings 

 by the statement he makes in the text, and we can only believe, 

 that Mr Eyton could have been led into such an apparent error 

 by having several specimens of the sternum of this bird at his 

 disposal, availing himself of one for his drawing and of another 

 for his description, perhaps at a later date. 



Now all the sterna I have examined of Cat h arista u r u b u 

 have two notches upon either side of the carina, yet Eyton figures 

 the sternum of this vulture with a large, elliptical foramen upon 

 either side in lieu of a pair of the notches [cf. "Cathartes 

 niger"]. 



The various forms taken on by the sternum of Cathartes a. 

 septentrionalis, and what I have said about them, applies 

 likewise to the sternum of Gyp arch us papa, and I have 

 examined a number of specimens and read Ey ton's remarks in the 

 case, too, both of which go to prove it. And, in short, it will prob- 



1 In my Osteology of the Cathartidae I present figures of these various sterna of 

 Cathartes a. septentrionalis, but those figures are not reproduced in 

 the present connection. 



