200 MEMOIRS OF THE CARNEGIE MUSEUM 



The ulna of the forearm is even much longer than this, being fully 32.5 centi- 

 meters in length, and from its great pneumaticity a very light bone. At its proxi- 

 mal extremity it has a very large pneumatic fossa just below the facet for articulation 

 with the radius. The olecranon process is barely at all developed. Along the 

 moderately curved shaft there are at least twenty-two distinct papillae, nearly equi- 

 distant from each other, for the insertion of the quill-butts of the secondary feathers 

 of the wing. On section, at its middle third, the shaft is triangular, and its distal 

 end presents us with nothing peculiar. (The ulna of P. sharpei is shown in PI. 

 XXVIL, Fig. 31.) 



The radius is a long, slender bone and is also somewhat curved. Its distal end 

 is transversely expanded, below, which expansion is the pneumatic fossa, 



The radiale and ulnare of the carpus both plainly show the pneumatic fossa 

 leading into them, as do all the bones of the manus. The carpo-metacarpus has 

 an extreme length of about 12.4 centimeters. Along its continuity it is slightly 

 carved anconad, while the very slender medius metacarpal stands well away 

 from the main shaft, being somewhat longer than it is at the point of anchy- 

 losis distally. The pollex metacarpal is short and bulky. The carpo-metacarpus of 

 P. sharpei exhibits the usual characters of this bone among the Pelicans (PI. 

 XXVIL, Fig. 39). 



The proximal phalanx of the index digit, with a length of 5 centimeters has 

 a broad expansion posteriorly, and is peculiar in being perfectly flat and smooth 

 upon its anconal side, while upon the palmar aspect it is divided into two 

 deep concavities which are absolutely riddled with pneumatic foramina at their 

 bases. 



The terminal joint of this finger is long and trihedral in form, with its pneu- 

 matic foramen at the proximal end. Though a little longer than the pollex 

 phalanx, the latter has very much the same shape, and is likewise pneumatic. The 

 free terminal joint of the medius digit has a broadish, triangular expansion behind, 

 and the holes for the admission of air pierce it upon both sides. This bone is 3.4 

 centimeters long, by 1.3 broad at its broadest part ; while the distal joint of index 

 has an extreme length of 4.6 centimeters. 



In the pelvic limb, a femur although pneumatic to a certain degree, it is not so 

 markedly so, as either the tibio-tarsus or the tarso-metatarsus. It will, in the dried 

 skeleton, probably weigh more than the former, notwithstanding it is not as large, 

 nor so long. Its stout shaft is but very little bowed in the antero-posterior direction, 

 and the extremities are large and massive. The broad trochanter does not rise above 

 the articular summit of the bone proximally, and the pit for the round ligament on 



