198 MEMOIRS OF THE CARNEGIE MUSEUM 



well-developed ribs ; one free dorsal ; three dorsals fused with the pelvic sacrum ; 

 fourteen in the pelvic sacrum ; and six caudals ; the pygostyle not being included 

 in this count. 



The sternum and os furcula are intimately fused together at the carinal angle, 

 forming there an extensive union. This is also the case in Pelecanus sharpei (PI. 

 XX VI 1 1., Fig. 42). Apart from this fact, the sternum has much about it to remind us 

 of that bone in Plialacrocorax. It is profoundly concave upon its dorsal aspect, and 

 correspondingly convex upon the opposite surface. Either costal border, trans- 

 versely very broad, is occupied nearly its entire length by the five hsemapopliysial 

 facets, with the long, shallow concavities that are between them. These latter are 

 riddled with small pneumatic foramina, while only a few of these openings are found 

 elsewhere in the sternum, and they are very minute. Two wide, shallow indenta 

 tions mark the xiphoidal margin, and the lateral xiphoidal processes are short with 

 rounded ends. They extend backwards and outwards. The deep keel projects 

 somewhat forwards, but is merged upon the surface of the bone behind long before 

 it reaches the posterior sternal margin. 



Each "costal process" is low and of a subquadrilateral outline. On the anterior 

 border of the bone there is a notable concavity, longitudinally disposed and of some 

 considerable breadth. It extends from the upper termination of the anterior and 

 rather sharp margin of the keel to lead into the general concavity of the dorsal as- 

 pect of the sternal body. It separates the long, narrow costal grooves in front, as 

 well as the rather deep costal facets above them. 



U-shaped in pattern, the lower loop of the os furcula is not particularly stout, 

 while the chief feature of this bone is its enormously swelled and enlarged free 

 upper extremities (PI. XXVIII., Fig. 42). 



These are entirely hollow, and each is provided with an elongated pneumatic 

 foramen upon its postero-mesial aspect. Postero-laterally, either one presents for 

 examination a subcircular facet for articulation with the head of the corresponding 

 coracoid, internal to which a stumpy, tuberous projection extends backwards. But 

 this fails by an extensive interval to meet the scapula, when the bones of the 

 shoulder-girdle are articulated as in life. The mesial and outer aspects of these 

 great clavicular heads are flat and smooth ; anteriorly, their thickened borders are 

 convex from above downwards, the posterior borders being concave. On top they 

 each present a flat, triangular surface with the apex to the front. 



From its extreme pneumaticity I find a coracoid in Pelecanus fuscus to be a very 

 light bone, while it has an altitude of 9.7 cm., being large in its other proportions. 

 The sternal end is considerably dilated, and to the other side is a very small up- 



