1901. J SHUFELDT — OSTEOLOGY OF THE CUCKOOS. 27 



smooth, the opposite side showing a broad, shallow groove for the 

 guidance of the tendons to the antibrachium. A fairly well devel- 

 oped " ectocondyloid tubercle" is seen at its usual site, on the 

 radial border of the shaft just above the oblique trochlea. 



Following the example of the humerus, we find the comparatively 

 short radius and ulna very much bowed along the continuity of 

 their shafts. This gives rise to a broad spindle-shaped interosseous 

 space, the two bones only coming in contact at their distal and 

 proximal extremities when articulated. 



The radius is not nearly so much bent as the other bone of the 

 antibrachium, and presents nothing peculiar about it. On the 

 other hand, the ulna, with its greatly curved shaft, its prominent 

 row of secondary papillae and its well-developed olecranon, is 

 quite a striking bone beside it. 



Composing the elements of the carpus, the two usual free seg- 

 ments are seen ; of these, the radiale has pretty much the same form 

 as it assumes among birds generally, while the ulnare takes on an 

 entirely different shape. It does not develop the two limbs or 

 processes that straddle the proximal extremity of the carpo-meta- 

 carpus when the bones are in situ, as in the vast majority of the 

 Class, but is simply a bar of bone, with one end enlarged and bear- 

 ing at its summit an articular facet for the ulna. 



The carpo-metacarpus is chiefly interesting for its peculiarly 

 formed mid-metacarpal. This is uncommonly broad at its proxi- 

 mal end and curiously twisted as it descends to anchylose with the 

 lower end of the index metacarpal, or main shaft of this compound 

 bone. So far as I have been enabled to discover, the phalanx of 

 pollex-digit does not bear a terminal claw, and the bone has the 

 usual form as seen in most birds. Nothing of note distinguishes the 

 two phalanges of the index digit, while the small phalanx of the 

 last finger develops, at the middle point of its hinder margin, a 

 curious little upturned spur. 



Of the Pelvic Limb. — As in the pectoral extremity, the proximal 

 long bone of this limb, the femur, is the only one in it that enjoys 

 a pneumatic condition. The site of the foramen that admits the air 

 to its hollow shaft is, however, quite unique, being upon the poste- 

 rior aspect of the bone, between the trochanter and head, instead of 

 on the anterior side, as usual, below the trochanter. 



This latter feature is not elevated above the articular surface at 

 the summit, and the semi-globular head is, comparatively speaking, 



