58 ODONTORNITHES. 



The cut given below will make plain these points in the scapular arch. 



Fig. 14. 



Figure 14.— Scapular arch of Sesperornis regalis, Marsh; side view; one-half natural size. s. scapula; 

 h. humerus;,/ clavicle, orfureulum; c. coracoid ; st. sternum. 



The Scapula. 

 (Plate VI, figure 7, and Plate VII, figures 5-7.) 



The scapula in Hesperomis is a small, slender bone, somewhat curved, 

 and of nearly equal width throughout its entire length. It is thickened at 

 its proximal end, and transversely truncated, the outline of the extremity 

 being subtrihedral. This extremity shows two articular facets, a small 

 inner one for union with the coracoid, and a larger triangular one, forming 

 the scapular portion of the glenoidal fossa. There is no acromial process. 

 The shaft is nearly of uniform width, and its outer surface is convex, 

 both fore and aft and transversely. The inner surface is concave longitu- 

 dinally. The distal half gradually expands, and the end is thin, and 

 spatulate. In its natural position in the skeleton, the scapula was nearly 

 horizontal, with its posterior extremity somewhat depressed, and incurved. 



The dimensions of the scapula in Hesperomis regalis are as follows : 



Measurements of Scapula. (No. 1476.) 



Length of scapula, 1 35.0""" 



Greatest diameter of proximal end, 12.0 



Transverse diameter of proximal end, 9.0 



Vertical diameter of glenoid articulation, 8.0 



Least vertical diameter of shaft, 7.0 



Width of distal end (approximate), 10.0 



