REPTILIA: VARANOSAURUS 101 



upward in the articulated skeleton. The upper end gradually 

 narrows, its flattened face in front and external. In the articulated 

 skeleton it lies against the front margin of the scapula, scarcely 

 overlapping it. As articulated, the two upper extremities of the 

 clavicles are less than two inches apart; the anterior border is 

 directed obliquely backward, the margin below projecting forward 

 and upward. As stated, no indications whatever have been dis- 

 covered in any skeleton of a clei thrum; it was assuredly absent. 



Humerus (Plate VI, Figs. 1-6). — The humerus is of the "old- 

 fashioned" type, broadly expanded at each extremity and with a 

 slender shaft in the middle. The planes of the two ends meet 

 each other in an angle of about seventy degrees, that of the proximal 

 turned outward from the horizontal. The proximal articular 

 facet is elongated, narrower at the inner than at the outer side; 

 its surface is moderately convex, with the chords of its curves 

 almost at right-angles to the planes of the proximal end, indicating 

 an almost horizontal position of the end in life. On the dorsal 

 side of this extremity, which is convex from side to side, there is 

 a considerable rugosity near the upper inner part, for muscular 

 attachment. The ventral surface is flat or gently concave for the 

 most part, and the lateral process is turned forward, so that its 

 thickened extremity looks ventrad and is placed at about the upper 

 third of the bone. The distal extremity is much more expanded 

 than the proximal. The articulations for radius and ulna are 

 turned somewhat ventrad; the larger inner one, for the radius, 

 arises mostly from the ventral surface, that for the ulna in large 

 part from the dorsal, on either side of which, on the dorsal side, 

 there is a rather deep groove. On the more thinly expanded inner 

 side, at about the lower third of the bone, is the large epicondylar 

 foramen, which pierces the bone from above downward and is 

 covered by a thin and slender bridge of bone. On the outer side, 

 above the condyle, there is a projection protruding beyond the 

 inner margin of the bone, from which it is separated by a narrow, 

 but deep vertical groove, a process characteristic of some, if not all, 

 the zygocrotaphic reptiles, but wanting often in the Cotylosauria, 

 especially the Pariotichidae. The expanded and somewhat angular 

 inner condyle has a facet of considerable size for the attachment 



