ADDITIONAL SIWALIK PERISSODACTYLA AND PROBOSCIDIA. 21 
greater development of tlie posterior accessory columns (a) in the Indian tooth. In 
the European tooth these are not larger than the anterior accessory columns (b), and 
do not extend on the outer side of the median longitudinal fissure ; this causes the 
blocking of the middle of the transverse valleys to be less complete than in the 
Indian tooth. In some European specimens^ the development of the posterior 
accessory columns is still less ; but in others again^ it is greater, although perhaps 
never quite so large as in the Indian tooth. Tliere is a considerable degree of 
variation in the size of the hind talon in European specimens. 
It appears, therefore, that the differences between the present specimen and the 
last lower molar of 3£. fmgustidens are scarcely, if at all, greater than those occurring 
between different European specimens of the latter ; and it thus seems probable that 
at the most they should be reckoned merely as of varietal value. The greater 
development of the accessory columns in the Indian tooth is a step from the typical 
form of M. angusiidens towards the more complex tooth of M. pandionis. 
In the following table the dimensions of the present specimen are compared with 
those of the corresponding teeth of M. pandionis^ and M. angustidend^ ; the specimens 
of the teeth of the two latter being in the same condition of wear as the Bugti tooth. 
Specimen. M. angustidens. M. pandionis. 
Total length 5'65 5.85 8'4 
Greatest width of first ridge . . . 2'38 2'6 3’3 
Height of first ridge .... TO 1-0 1-8 
,, ,, hind talon .... T35 0’8 2‘6 
A smaller tooth of M. pandionis has a length of 7'4 inches. The European 
molar of M. angustidens is an unusually small one. 
Second upper true molar . — The tooth represented in plate IV., fig. 2, belonged to 
the same individual as the last specimen.® The regular oblong form of the crown 
shows that it belongs to the upper jaw; while the presence of but three ridges, 
which are more worn than those of the last lower tooth, shows that it must be the 
second true molar : it belongs to the left side of the skull. The tooth exhibits a 
large concavity on its anterior surface, caused by the pressure of the preceding 
tooth : the crown is so worn that the dentine surfaces of the outer and inner columns 
of the two first ridges have coalesced ; and have also united with those of the 
accessory columns. In the last ridge the internal column is still separate, and the 
position of the large anterior accessory column® [a) can still be detected : the hind 
talon {ta) was evidently well developed; and the large tubercles can be seen at the 
inner extremities of the transverse valleys. 
This tooth agrees in all general characters with the corresponding molar of 
31. angustidens ; but is intermediate in size between European specimens of i and 
1 Vacek, ‘ Afifiand. k. k. geol. Eeicli vol. VII , pt. 4, pi IV , fig 2 
2 Compare a specimen figured by De Blainville— “ Osteographie,” Genus Elepbas, pi. XV. 
3 Supra., vol. I., pi. XXV., fig. 4. 4 Meyer, op. cit. 
5 Inferred from the precise similarity in the mineral condition of the two specimens ; and from their agreement in size, 
and their relative condition of wear. 
3 This corresponds to the larger, or posterior, accessorj^ column in the lower teeth. 
F 
