CRANIA OP RUMINANTS PROM THE INDIAN TERTIARIES. 61—148 
Widtli of narrowest portion of parietals 
Interval between supra-orbital foramina 
Length of temporal fossa 
„ intercornual ridge 
Inches. 
2-4 
3'1 
68 
3*0 
The measurements of two other specimens of cranium of this species collected 
by Mr. Theobald from Siwalik strata are as follows : — 
Width at superior border of orbits 
8-0 
7-9 
„ constriction above orbits 
7-2 
0-0 
Interval between occipital crest and intercornual ridge 
6'3 
50 
Width of narrowest part of parietals 
2-4 
2-8 
„ occipital through petrosals 
7-2 
7'6 
Height from lower border of foramen magnum to crest 
.4-8 
4-5 
Interval between external angles of condyles 
. . . . 4-5 
5-2 
Length of intercornual ridge .... 
1-7 
2-2 
Prom the above measurements it will be i 
seen that the latter of 
these two 
specimens differ from the first specimen in having 
a wider and lower occipital region 
and larger occipital condyles ; the occipital crest forms a lower and flatter arch. 
The parietals between the temporal fossae are also wider, and the horn-cores are of 
smaller dimensions, and directed more outwards. 
The specimen drawn in Plate H, fig. 6, of the unpublished plates of the “ Pauna 
Anti qua Sivalensis” has the bases of the horn-cores set much farther apart than in 
any of the above specimens, the interval between them being nearly six inches in 
length. 
The teeth of all the specimens in the Indian Museum are in a very imperfect 
and damaged condition, but a few of them show that they were provided with 
the accessory median tubercle so characteristic of the oxen. 
We may now consider iu what points the cranium of the present peculiar 
genus is related to allied groups of Ruminants ; firstly, we find that the jiosition 
of the horn-cores, which are placed on a ridge of the frontals far in advance of or 
below the plane of the true occipital surface, and almost directly above the orbits, 
together with the distinctness of the planes of the occiput and the parietals, 
distinguishes the genus from all the true oxen, both recent and fossil, and approxi- 
mates it to the antelopes and goats. Prom the true antelopes, however, the 
cranium of Semibos is distinguished by the form of its horn-cores ; no recent 
antelope has triangular horns, although those of Antilo'pe cordieri of the Miocene 
Tertiaries of Montpelier are angulated in front ; it is also distinguished from this 
group by the non-depression of the facial surface of the lachrymals and by the 
absence of any trace of the infra-orbital vacuity. 
Among the aberrant antelopes and thefi allies we find that the cranium of 
Semihos at first sight presents a considerable general resemblance to that of 
Tragocerus amaltlieus from the Miocene Tertiary of Attica in both genera the 
planes of the frontals and the parietals form an obtuse angle with each other, and 
' Gaudry : “ Animauz Fossiles et Geologie. de 1’ Attique.” PI. XLIX. 
