1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 285 



old Cormorants, and direct and extensive articulation in Sulci, and, if* 

 my memory serves me right, something of the kind takes place in Pele- 

 canus and Tacliypetes. 



The coracoid, though short, is extremely stout and massive in struct- 

 ure. The antero-posteriorly compressed shaft amounts to little more 

 than a constriction between the head and wonderfully expanded sternal 

 extremity. 



The base of this latter possesses articular facets to correspond with 

 those described on the sternum; the outer small one being connected 

 with the large inner one by a gently concave and thin border. 



Each extemo-lateral angle of the base of a coracoid is produced as 

 in the Fulmars and Petrels; it is here, however, a broad, quadrate proc- 

 ess, instead of being carried out to a point, as in the latter birds. A 

 coracoidal head is much flattened at its summit and smooth, while as 

 a whole this tuberous extremity is directed forward and inward to 

 develop a shallow facet upon its mesial aspect for the furcula to artic- 

 ulate with, as described above. 



Fig. 23. The shoulder-girdle of Diomedea albatrus; anterior view; life size. By the author, from 

 specimen 3333, Smithsonian collection. Collected by E. Herendeen at Cook's Inlet, Alaska. 



Its scapular process is situate rather high upon the shaft, being 

 concave from side to side in front, and rather flattened behind. Usu- 

 ally it is pierced by the foramen found in so many other of the water 

 birds, and here quite close to the coracoidal shaft. 



The glenoid cavity is comparatively small, so far as it is formed in 

 bone, and no doubt in life its proper size is attained through the assist- 

 ance of other structures. Coracoid and scapula offer each about the 

 same proportional amount of surface to it as commonly seen among 

 birds. A scapula is not much decurved along its blade, and this part 

 of the bone is thickened, being nearly of an equal width throughout 

 its length, though somewhat dilated at its hinder extremity, terminat- 

 ing in a rounded apex. Its head articulates with the entire width of 



