SIWALIK AND NARBADA BUNODONT SUINA. 45—79 
fossil forms of intermediate size, to indicate any characters by which the one can be 
satisfactorily distinguished from the other ; and comparisons will, therefore, be 
mainly confined to the -S', andamanensis group. It may be observed, however, that 
the talon of the third molar of S. andamanensis is generally still simpler than that of 
*S. vittatiLS ; and the length of that tooth usually still less in joroportion to that of 
the two 2 )receding teeth ; and that in this respect the fossil appears to be nearer to 
the former species. Compared with the cranium of 8. andamanensis, the fossil form 
agrees with that species in the proportionate length of the true molars ; the united 
length of m. 1 and m. 2 considerably exceeding that of m. 8 ^ and the talon of the 
latter being relatively short : the true molars of the fossil are, however, relatively 
wider than those of the existing species. Both forms agree in the relatively early 
appearance^ of m. -3 ; fiat the crown of that tooth is lower in the fossil, and the talon 
wider, with its hinder portion (h) more distinctly separated from the hinder joair of 
main columns : the last tooth of the existing species has not the conspicuous cingulum 
of the fossil. The upper molars of 8. timorensis and 8. papuensis (the other members 
of the 8. andamanensis group) are also very similar to those of the fossil, but have 
likewise slightly narrower and higher crowns. The crania of the three existing 
species have the pre-orbital concavity wide posteriorly. The last upper premolar of 
the fossil has its inner moiety longer antero-posteriorly, and its inner column {a) 
decidedly larger than in either of the three species mentioned, or indeed than in any 
existing Asiatic pig ; and the preceding tooth^ likewise appears to be relatively larger. 
In these respects the fossil is nearer to the African 8. porcas^ ; which is, however, 
distinguished by the smaller relative size of m. 3 , and the absence of pm. 1 5 the latter 
being well developed in the fossil. 
Loiver dentition and mandible. — In plates LXX., LXXI., of the “ F.A.S.” there 
are represented five specimens of the mandible of a small species of Siwalik pig, 
which from their size and the structure of their teeth may be referred to the joresent 
species. The first specimen (plate LXX., figs. 3, 3a) shows the entire cheek- 
dentition of both sides, in an early stage of wear : the second (pi. LXXI., fig. C) the 
cheek-dentition of the left side, the earlier premolars and m. 3 being imperfect, and 
mTl in a half-worn condition: the third [ibid, fig. 10) the last five teeth of the right 
side in a rather more worn condition : the fourth {ibid, fig. 8 ) m. 2 and m. 3 of the left 
side, in a well-worn condition ; and the fifth {ibid, fig. 11 ) the symphysis, showing the 
four premolars. In plate VIII., figs. 3, 3a, of the present volume there is represented 
the dentition of the right ramus of a similar mandible collected by Mr. Theobald in 
the Siwaliks of the Potwar district of the Punjab, showing the last five cheek-teeth 
in a well-worn condition. In figure 2 of the same plate there is represented a 
fragment of the right ramus showing m. 3 and the greater part of m. 2 , both in a still 
1 The specimen represented in pi. LXXI., fig. 9, of the “ F.A.S.” is abnormal in this respect. 
2 “F.A.S.,” pi. LXXI., fig. 9. 
3 The upper and lower dentition of this form is figured by Riitimeyer in ‘ Vcrhand. nat. Ges. Basel,’ vol. IV., p. 517, 
et. seq , under the name of S. poiioiUatus. 
