8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



end of the bone, where the tendinal attachments are weakened, a 

 condition noted in the scar for the pronator brevis, in the flattened 

 face of the entepicondylar prominence, and in the area of the 

 ectepicondyle. 



The form of the humerus as a whole is definitely that of a bird 

 of reduced volant ability, notable particularly in a group of birds 

 whose living species are strong in flight. 



Ulna. — The material includes six proximal and six distal ends, with 

 two additional segments of the shaft. These fragments corroborate 

 the character of humerus and carpometacarpus in evident reduction 

 in size. In addition the impression for the brachialis anticus, and 

 the development of the other parts of the head are less in size and 

 strength, characters that are repeated in relative form at the distal 

 articulation. Though the reduction is less marked than in the wing 

 elements on either side the indication is that of lesser power. The 

 weakened papillae for attachment of the secondaries in particular give 

 this impression. As the material is fragmentary, no definite measure- 

 ment of the total length is available. 



Radius. — The only part preserved is a section from the distal end, 

 which indicates a reduction in size with a definite flattening of the 

 shaft. 



Carpometacarpus. — The eight specimens, three from the right side 

 and five from the left, show the characters of this bone fully (except 

 for the distal half of metacarpal III which is missing), and verify 

 fully the supposition of reduction in powers of flight in this inter- 

 esting species. The bone as a whole retains the bulk and strength 

 found in living Grus canadensis but is only four-fifths as long. This 

 shortened length has come in the distal area as the proximal end is 

 as large as in the modem species with the parts of equal size and 

 development. The reduction is evident particularly in the length of 

 the shaft between the head of the bone and the proximal end of the 

 intermetacarpal opening, and in length from the opposite end of the 

 same open space and the distal margin of the bone, this being only 

 half the length of the modern bird. 



Second digit of first phalanx. — The single complete bone is about 

 one-third shorter than in small Grus canadensis, though it is nearly 

 as high in its central area. The details of form otherwise are like 

 those in the larger bird. 



The lessened length is another indication of the shortened wing. 



Coracoid. — One nearly complete bone and three fragments indicate 

 clearly a considerable reduction in size in this area of the skeleton. 



