ELEPHAS PRIMIGENIUS.— HUMERUS. 153 



instances where the groove was fully as open as in the African. Looked upon, however, 

 generally, the above is fairly reliable in the diagnosis of the two species. 



4. As to degrees of saliency of the supinator ridge; individual instances in the Asiatic 

 appear precisely to accord with 708h of the African. The ridge was less salient in many 

 instances of the former, but here again there seems so much variability that one is not 

 disposed to place much reliance on this character. Compare fig. 4 with 5. 



5. The ridge proceeding from the supinator upwards and backwards to the epiphysis 

 is very often so pronounced in the Asiatic as to form a carina at its upper part, and would 

 be of value if invariably persistent, but it is not so, being sometimes, as in 708h African, 

 lost before it reaches that point. Compare fig. 4 a with 5 a. 



6. As to the position of the nutritive foramen, when one is present and of conspicuous 

 size to entitle it to be considered the main opening, there appears considerable incon- 

 sistency as to its exact position in the Asiatic Elephant, but when at all pronounced it is 

 usually in a line with the apex of the supinator ridge, whereas in 70Sh it is in the 

 lower third. In fossil specimens it is so frequently obliterated by mineral infiltra- 

 tions as to be quite undiscernible ; moreover, the multiplicity of these canals on various 

 parts of the shaft, and their agreement in size, make it uncertain which to rely upon as 

 the normal condition. 



7. With reference to the configuration of the distal articular surface, the following 

 points are referred to by Busk, 1 which, if persistent in the African, as they are in all 

 adult humeri of the Asiatic I have examined, would be invaluable in establishing specific 

 characters. These refer to the (a) contours of the outer condyle ; (b) the configuration 

 of the arc formed by the lower border of the articular surface ; and (c) the contour of 

 the trochlear depression posteriorly, as shown in his monograph referred to on the 

 Maltese fossil Elephants. 1 



The above characters are, viz. : 



(a) A more globose margin and general contour of the external condyle in the African. 

 This is pronounced in 708h, whereas the same parts are less rounded in the Asiatic. 

 Compare fig. 5 b with fig. 4 b. 



(b) The arch of the lower border formed when the humerus is placed erect on a level 

 surface is shorter and nearly central in the African, whereas in the Asiatic it commences 

 gradually from the margin and extends from nearly one to the other. Compare fig. 5 b 

 with fig. 4 b. 



(c) The trochlear depression below the pit is narrow in the Asiatic, with nearly 

 perpendicular sides, whereas it is shallow in the African, with gently undulating margins, 

 in fact, as in the case of the bicipital groove, the one is deep and narrow, and the other 

 broad and shallow. Compare fig. 4 b with 5 b. 



8. The depth of the olecranon pit and the hollow surface above it are seemingly 

 greater in 708h African than I have seen in the Asiatic. These, however, may be con- 



1 'Trans. Zool. Soc. London,' vol. vi, p. 257. 



