676 



PROF. H. €r. SEELET 0~N THE EEPTILE 



in the deposit, especially in the slenderness of the shaft and relatively 

 small size of the articular ends, as well as in the circumstance that 

 the articular extremities were at right angles to each other. Unfor- 

 tunately both proximal and distal ends are lost by decomposition. 

 The left humerus is best preserved proximally, while the right 

 humerus extends further distally. The length indicated by the two 

 bones without reaching the articular ends is 14 centim. ; so that 

 the entire length of the bone, when perfect, was at least 2 centim. 

 more. The left fragment (fig. 8) is fully 12 centim. long, and, when 

 placed with the distal end uppermost, shows a slight convexity on 

 one lateral margin and a corresponding concavity on the other, 

 the concavity facing the anterior and inferior aspect of the bone, 

 the convexity being superior. Owing to the circumstance that the 

 proximal end is absolutely at right angles to the distal end, it hap- 

 pens that the shaft of the bone widens distally. The transverse 

 measurement at the base of the radial crest (fig. 9) is 1| centim., and 

 at the distal fracture 23 millim. (fig. 10) ; and it is still widening. 



The superior distal surface is convex from side to side, with a slight 

 ridge towards the radial side of the bone, which is really a prolon- 

 gation of the muscular ridge of the radial crest, which in crocodiles 

 never extends along the superior aspect of the bone. This ridge 

 produces a flattened radial aspect, a slight approximation to which 

 may be observed at the distal articular end of the crocodilian hu- 

 merus ; but here it gives a somewhat compressed and sharp aspect 

 to the inferior radial margin of the bone along the distal half of the 

 shaft, while the ulnar side is relatively flattened or rounded. The 

 bone is marked, on the superior aspect especially, with strong longi- 

 tudinal striae or slightly elevated ridges. Its thickness at the distal 

 end, as preserved, is about 13 millim. ; but the right bone is a 

 trifle stouter. The inferior aspect is flattened distally with a slight 

 longitudinal depression. The proximal end of the bone necessarily 

 widens, while the shaft remains comparatively uniform. The su- 

 perior surface is smooth, and convex from side to side, but slightly 

 channelled towards the expanded radial process, which is necessa- 

 rily placed on the middle of the aspect which, when viewing the 

 distal end, would be regarded as superior. The width of the 

 proximal end appears to have been small. The lower part of the 

 radial crest gives a transverse width, as preserved, of less than 

 2| centim. The inferior aspect of the proximal end is longitu- 

 dinally channelled, and thus divided into a compressed anterior 

 process and a rounded and somewhat inflated inferior and posterior 

 part. The thickness of the bone here at the fracture is just over a 

 centimetre. The whole inferior surface, not only of the radial crest 

 but of the adjacent region of the bone, is roughened with powerful 

 muscular attachments. The right fragment substantially repeats 

 these characters ; only the bone is appreciably stronger, with its 

 muscular ridges more marked, and in length shows a decided sig- 

 moid curve, like that which marks the humerus of a crocodile. I 

 am led to refer these bones to the same species as is indicated by 

 the femora next described. In this case they would indicate an 



