WINGS OF ICHTHTORNIS AND APATORNIS. 151 



Measurements of Humerus. (Ichthyornis victor, No. -1447.) 



Length of right humerus, 71.5 mm 



Anteroposterior extent of proximal articulation, 17.6 



Transverse diameter of proximal articulation, 4. 



Transverse diameter of distal articulation, 11.2 



Greatest diameter of radial condyle, 5.5 



Measurements of Humerus. [Ichthyornis victor, No. 1452.) 



Greatest diameter of proximal articulation, 16.3 mm 



Transverse diameter of proximal articulation, 3.9 



Greatest diameter of distal end, 12.1 



Greatest diameter of radial condyle, 6. 



Measurements of Humerus. (Ichthyornis victor, No. 1457.) 



Greatest diameter of distal end, 11. mm 



Antero-posterior diameter of radial condyle, 5.2 



Vertical diameter of radial condyle, 6.5 



Diameter of shaft, 5.5 



Measurements of Humerus. (Ichthyornis tener, No. 1738.) 



Greatest diameter of distal end, 7.5 mm 



Antero-posterior diameter of radial condyle, 3.3 



Vertical diameter of radial condyle, 4.5 



The Radius. (Plates XXIV and XXX.) 



The radius like the other bones of the wing in Ichthyornis is strong 

 and robust. The proximal end is of moderate size, and presents a 

 sub-elliptic, slightly concave, articular face for the condyle of the humerus, 

 and a slight lateral facet for the ulna. Nearly opposite this facet, the 

 bone is distinctly tuberculated, and on the side toward the ulna at a short 

 distance from the proximal end is a distinct elongate oval facet, raised on 

 a tubercle above the general surface of the bone. This tubercle appears 

 to give the shaft of the bone a short proximal bend toward the ulna. It 

 then becomes nearly straight, until beyond the middle it curves again 

 gradually toward the ulna, and at the end is moderately expanded and 

 thickened. The distal articular surface for the ulna is indistinct, while 

 that for the radial carpal is, as usual, elongate and convex in both 

 directions. 



