152 ODOXTORXITHES. 



In the genus Apatomis, the face for articulation with the humerus is 

 nearly flat, while the ulnar articular surface is more distinct, and extended 

 upon the side of the bone, as in Graculus. The shaft of the radius is 

 hollow in both genera of Odontotomies. 



The following measurements will show the principal dimensions of 

 the radius in this group : 



Measurements of Radius. (Ichthyomis dispar, No. 1450.) 



Diameter of shaft, 2.0 mm 



Greatest diameter of distal end, 5.5 



Least diameter of distal end, 3.0 



Measurements of Radius. (Ichihyomis victor, No. 1741.) 



Length of radius, 71. mm 



Greatest diameter of proximal end, 5.2 



Least diameter of proximal end, ........ 3.8 



Diameter of shaft, 3. 



Transverse diameter of distal end, 7.3 



Least diameter of distal end, 4. 



Measurements of Radius. (Ichthyomis victor, No. ] 733.) 



Greatest diameter of proximal end, 4.6 mm 



Least diameter of proximal end, 3.5 



Diameter of shaft, 2.8 



Greatest diameter of distal end, 6.1 



Least diameter of distal end, 3. 



Measurements of Radius. (Apatornis celer, No. 1734.) 



Greatest diameter of proximal end, 4.2 mm 



Least diameter of proximal end, 3. 



Diameter of shaft, . . - 2.2 



The Ulna. (Plates XXIV and XXX.) 

 The ulna in IcMhyornis is a strong moderately curved bone, some- 

 what trihedral proximally, but becoming more nearly cylindrical toward 

 the distal end, where it is also less curved than in the proximal half. The 

 surface for articulation with the humerus is placed more obliquely to the 

 shaft of the bone than in Sterna, and occupies a greater proportion of the 



