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Show 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 2 some fragments of molars of a stegodont Elephant from Java, which he thinks may probably belong either to Elephas insignis or E. bombifrons3. At a still later date teeth of Siwalik species of Elephas and Mastodon have been described by Dr. E. Koken 4 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 5, 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 insensibly into other species. Thus the normal number of ridges in the "intermediate" molars is four, but a fifth is occasionally present6, 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. perimensis, 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 tetralophodont M. perimensis appears again to show indications of passing into M. pandionis7, in which the intermediate molars have but three ridges. Not only is there, therefore, no real distinction between 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 upper true molar of a dwarf race of Mastodon latidens, in an early stage of wear, from near Bruni, Borneo. Tbe specimen is drawn of tbe natural size, as viewed from the grinding-surface (fig. 1) and from the outer side (fig. 2); ta, bind talon. 1 ' Palffiontograpbica,' vol. xxviii. art i. (1881). See also ' Palasontologia Indica,' op. cit. vol. ii. pp. 65-66. 2 ' Beitrage z. Geol. Ost-Asiens nnd Australiens,' in Sanimlungen d. Geol. Beich. Mus. in Leiden, no. 10 (1884). 3 Herr Martin mentions a previous notice by Jungbun in 1857 of similar remains discovered by himself in the mountains of Pati = Ajam, near Japara, in Java. 4 PabEontologische Abhandlungen; vol. iii. pt. 2 (1885). •' Vide Naumann, op. cit. 0 Vide Pal. Ind. ser. 10, vol. i. pi. xxxviii. 7 Ibid. vol. iii. p. 153. |