1885.] TOOTH OF MASTODON LATIDENS. 779 



Elephants ranged into China ; and Dr. E. Naumann ^ has indicated 

 the occurrence of several of these species in Japan ; while more 

 recently Herr K. Martin has described and figured " some 

 fragments of molars of a stegodont Elephant from Java, which he 

 thinks may probably belong either to Elephas insiynis or E. 

 bombifrons ^. At a still later date teeth of Siwalik species of 

 Elephas and Mastodon have been described by Dr. E. Koken ^ from 

 Western China. 



It thus seems that the Pliocene proboscidean fauna of India 

 extended into the extreme east of Asia, where, from its association 

 with Elephas namadicus and E. primigenius ^ it probably] persisted 

 into the Pleistocene. As much interest will attach to the discovery 

 of other remains of the Order from these regions, the attention of 

 travellers and collectors may be particularly directed to their 

 acquisition. 



It may be added that Mastodon latidens is an interesting form, 

 since it is one that apparently passes insensiljly into other species. 

 Thus the normal number of ridges in the " intermediate " molars is 

 four, but a fifth is occasionally present ^, in which case there is but 

 one step to the simplest of the stegodont Elephants, viz. Elephas 

 clifti, in which there are six ridges. In the opposite direction, by 

 a slightly increased development of accessory columns and the 

 heightening of the ridges, an approach is made to the tetralophodont 

 M. perime7isis, and although typical teeth of the two species are very 

 distinct, yet there are specimens in the British Museum of which it 

 is very difficult to say to which species they belong. The tetra- 

 lophodont M. perimensis ap[)ears again to show indications of passing 

 into M. pandionis '', in which the intermediate molars have but 

 three ridges. Not only is there, therefore, no real distinction be- 

 tween Mastodon and Elephas, but it is more than doubtful whether 

 individual species of the two can be always differentiated. 



DESCRIPTION OF PLATE XLVIII. 



The third left ujjper true molar of a dwarf race of Mastodon latidens, in 

 au early stage of wear, from near Bruni, Borneo. Tlie specimen is drawn of 

 the natural size, as viewed from the grinding-surface (fig. I) and from the 

 outer side (fig. 2) ; ta, hind talon. 



' ' Palseontographica,' vol. xxviii. art i. (1881). See also ' Palseontologia 

 ludica,' op. cit. vol. ii. pp. 65-fi6. 



- ' Beitrage z. Geol. Ost-Asiens und Australiens,' in Sammlungen d. Geol. 

 Reich. Mus. in Leiden, no. 10 (1884). 



^ Herr Martin mentions a previous notice by Junghun in 1857 of similar 

 remains discovered by himself in the mountains of Pati= Ajam, near Japara, in 

 Java. 



^ Palreoutologisclie Abhandlungen, vol. iii. pt. 2 (1885). 



^ Vide Naumann, op. cit. 



* Vide Pal. Ind. ser. 10, vol. i. pi. xxxviii. 



■^ Ibid. vol. iii. p. 153. 



