126 BRITISH FOSSIL ELEPHANTS. 



The last true molar of the Asiatic Elephant attains not unfrequently to the maximum 

 limit of that of the Mammoth, but I have not seen an entire tooth with a lower ridge 

 formula than x 20 x, whilst the average is about .v 22 x. Indeed, although the Asiatic 

 Elephant goes hand-in-hand in all its leading characters with the Mammoth, it maintains 

 more regular averages of the various members of the dental series than the latter. 



The affinities, therefore, between the ridge formulae of the Mammoth and the Asiatic 

 Elephant are of the most intimate character, and there seems a close relationship in that 

 respect between the last and U. Armeniacus and E. Columbi, which are apparently closely 

 correlated, not only as regards the ridge formulse, but also the morphological characters of 

 their grinders. Dr. Falconer was impressed with the relationship between the former and 

 the Asiatic Elephant, but considered the latter Elephant to be " between E. antiqims and 

 E. Indicus."^ I must observe, after repeated comparisons of the dental materials of 

 E. Armeniacus and E. Columbi, available in the British Museum and Royal College of 

 Surgeons, with those of E. Asiaticus, E. primigenius, E. antiquus, E. Namadicus, and 

 E. Hymdricus^ that I fail to distinguish distinctive characters of any value between the 

 molars of the Asiatic and the so-called Columbian or American and the Armenian 

 Elephants ; so that, as far as teeth are concerned, the existing species may be the survivor 

 of an Elephant whose fossil remains have turned up in Italy (?), Turkey in Asia, and 

 throughout the temperate regions of North America. 



The last molar of E. antiqims, especially the broad-crowned variety, might be mis- 

 taken for that of the Mammoth, and the same might be said of the E. meridlonalis ; and 

 although the ridge formulae might not be of assistance as regards the diagnosis with 

 reference to the two former, still, in entire specimens and in crowns sufficiently detrited to 

 show the pattern, I can scarcely conceive that in practised hands there would be much 

 difficulty with reference to E. meridionalis. The lower ridge formula of the latter, 

 apparently rarely rising above seventeen ridges altogether, with the massive proportions 

 of the crown constituents, and its absence, with doubtful exceptions, from the deposits in 

 which Mammoth remains are found, render its molars of easier distinction. 



The ridge formula of the Mammoth, according to the latest differentiations made by 

 Falconer, stood thus after eliminating talons : 



Milk Molars. True Molars. 



4 8 12 12 16 24 



He maintained a theory that these figures were expressive of the usual number of 

 plates in the six molars. Now, were the above in any ways general, their use as 

 exponents of the ridge formula of the species would at all events be of taxonomial value. 

 But from the data here furnished this nmst appear questionable, and I have no hesita- 

 tion in stating that, were the collections on the Continent of Europe carefully examined, 

 the range of the ridges in each member of the series might be further extended. 



' Op. cit., vol. ii, pp. 447 and 214. 



