111—24 CRANIA OF RUMINANTS FROM THE INDIAN TERTIARIES. 
between the hom-cores and the orbits are rather less deep, and the centre of the 
forehead is rather more prominent : the horn-cores tend more directly outwards 
with only a very slight cmve forwards. On the occipital aspect the chief difference 
is that the vertical diameter of the infra-cristal portion is considerably greater in 
proportion to the transverse diameter in the Siwalik species ; this gives the whole 
occiput a more quadrate appearance, by which it approaches, as before said, more 
closely in form to the occiput of the true Taurine oxen, like Bos primigenius. The 
occiput of Falconer’s Nerbudda specimen forms a transition from the Siwalik 
species to the occiput of our large Nerbudda specimen {Blate XVI, Jig. 1), in which 
the long transverse diameter of the occiput and the separation of the infra-cristal 
portion of the same surface is a character approaching to the occiput of Bibos- 
The occipital crest of our specimens of the Nerbudda species {Blate XVI, Jigs. 1^3) 
is completed in a single simple curve, whereas the proper occiput of the Siwalik 
species has high lateral borders at first scarcely curving at all, and with marked 
angles at their junction with this superior border ; the indentations of the temporal 
fossge on to the occiput are very shallow and are placed much below the level of the 
summit of the occipital crest or curved line. In the Nerbudda species, these in- 
dentations are somewhat larger, and are placed nearer to the level of the occipital crest : 
in all the above characters Falconer’s specimen of Bos namadicus is intermediate 
between the Siwalik cranium and the typical Nerbudda crania. 
In the Indian Museum there is another similar frontlet of an ox (No. 141), 
also collected in the Siwaliks by Mr. Theobald, which I refer to the same species 
as the last specimen, though it presents some slight differences in form. The speci- 
men comprises only the intercornual portions of the frontals, with the upper part 
of the occiput and the bases of the horn-cores. The dimensions are as follows : — 
Length of intercornual ridge ......... 7‘2 
Interval between occipital crest and intercornual ridge . . . . . . 1'8 
Width of occiput between temporal fossae ....... 7 0 
Circumference of base of born-core . . . . . . . • 14'5 
These few measurements agree nearly with those of the last specimen : the 
cross section of the horn-cores, however, exhibits a more nearly circular form, 
though the horn-cores themselves are directed upwards and outwards, with no incli- 
nation forwards. The occipital surfaces of this and the last specimen are almost 
identical in form, the curved line or crest extending high up between the hom- 
cores ; in the second specimen, however, the intercornual ridge is raised up into 
a median prominence, as in the figured specimen of the Nerbudda species. 
We may now compare the cranium of this Siwalik species with that of the 
European Bos primigenius in order to see in what points it differs from that most 
typical form of Taurine Oxen. Turning first to the occipital surfaces of the two 
crania, we shall find that the occiput of the Siwalik species is much more close to the 
European form than is the occiput of Bos namadicus. In both the European 
and the Siwalik crania, the summit of the occipital crest extends high up between 
