1838.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 283 



These shielding lips of bone are well seen upon the pectoral view of 

 the sternum shown in Fig. 20. 



A lateral view (Fig. 2x) shows the spreading costal process; the 

 wide costal border below it, with the foramina between the haemapoph- 

 ysial facets; the smooth and convex sternal body, and the thick and 

 fairly well-developed carina. 



Fig. 21. Eight lateral view of sternum of Diomedea albatrus ; life size. By the author, from speci- 

 men 3333 of the Smithsonian collection. 



The anterior border of this latter is concave forward, while its inferior 

 one is nearly straight and stops short of the xiphoidal end of the body. 

 The cariual angle juts out quite prominently and is thick through and 

 through, the inferior border being produced and expanded upon it. 



Eegardiug it from a pectoral aspect, we find the general outline of the 

 bone to be nearly square, with its hinder margin exhibiting one deep 

 notch, with the convex side forward and the postero lateral angles 

 rounded. Analyzing this, however, we see that each postero-lateral 

 portion is made up of one large subcordate process, due to the great 

 median notch above alluded to, and shallow concave notches, which 

 occur, one on either side, just behind the costal borders, and a median 

 xiphoidal pair, one on either side of the produced middle part of the 

 bone. 



This sternum of the Albatross differs principally from the sternum 

 in Eodgers' Fulmar in its being pneumatic, its method of articulation 

 with the coracoids, and the form assumed by its xiphoidal border. Ph/- 

 finus differs from both of them in having its xiphoidal border distinctly 

 and profoundly two-notched, agreeing in this respect with most of the 

 Jaegers and Gulls. 



