BAETTHEEIUM. 175 



arises from the union of the two rounded ridges which form the outer and inner 

 borders of the coronoid fossa ; it runs outwards and upwards, forming a crest which 

 projects strongly outwards and then a httle backwards. There is also a ridge running 

 up the front of the shaft from the lower end of the deltoid ridge. The head of the 

 bone seems to have been large and rounded, but in no specimen is the ujpper end 

 sufficiently well preserved for description. 



The great expansion of the distal end of this humerus, arising from the large size 

 of the condyles and the strong development of all the ridges and processes for the 

 attachment of muscles, seems to indicate that the fore limb was employed for some 

 other purpose than mere progression on land, possibly for digging or scraping up 

 the ground. Apart from this great distal expansion the humerus is somewhat 

 similar to that of TJintatherium, resembling it in the small and deep olecranon 

 fossa, the presence of the ridge running up the shaft from the lower end of the 

 deltoid crest. At least, it may be said that this humerus is much more similar to 

 that of the Dinocerata than it is to that of any Proboscidean. The differences from 

 the humerus of Arsinoitherium are very considerable (cf. text-fig. 1.6) ; in that genus 

 the form of the deltoid crest is different, there is no anterior ridge running up the 

 shaft, while the form of the outer condyle and supinator ridge is dissimilar and 

 approaches rather the Proboscidean type. 



A nearly complete specimen of the left radius (PI. XVII. figs. 8, 8 A, 8 b) was found 

 in association with the upper and lower jaws above described. In general form it 

 greatly resembles the radius of TJintatherium. The upper articulation for the humerus 

 is very wide and consists of two parts, a much larger outer portion (o.), oval in outline 

 with its long axis transverse and nearly twice the length of the antero-posterior axis ; 

 this surface is slightly concave in all directions. The other portion [i.) is very small 

 and bent down at an angle with that just described; it helped to form the articulation 

 for the inner portion of the trochlear surface of the humerus. Beneath the expanded 

 proximal portion, the shaft becomes trihedral, one angle being anterior while the flat 

 posterior face appears to be roughened for union with the ulna. Towards the distal 

 end the bone expands enormously : its posterior or postero-external face is deeply 

 concave and must have fitted closely against the inner side of the ulna ; the antero- 

 internal surface is convex. The very large distal articulation is incomplete on the 

 outer side, and consists of two facets separated by a prominent ridge. Of these facets 

 the smaller {so.) for the scaphoid on the inner side is triangular in outline and 

 concave from before backwards. The larger facet {lu.) for the lunar is concave in front 

 and slightly convex posteriorly. It will be seen that this form of distal articulation 

 is quite different from that found in the radius oi Arsinoitherium {&ee text-fig. 17) 

 or in Elephas, and that the structure of the carpus must also have been difi"erent, the 

 scaphoid forming a relatively large share in the carpal joint compared to what it does 

 in the two genera referred to. In fact, both in its distal articulation and in its general 

 form the radius here described resembles that of Uintatherium fairly closely. 



