95—8 CRANIA OR RUMINANTS UROM THE INDIAN TERTIARIES. 
Eefore proceeding to specific descriptions, it may be well to state that in the 
present work I have used generic terms in contradistinction to sub-generic terms, 
in all cases ; one reason for this is, that the crania of the different forms of extinct 
oxen generally differ from one another, more than do the crania of JBos and Buhalus, 
which latter are frequently considered as generic, and not as sub-generic divisions. 
If sub- generic terms were to be used in any case among the oxen, it appears to me 
that they should be used in all cases, and that consequently all the forms of oxen' 
described in the present Memoir should then be considered as belonging to different 
sub- genera of one large genus Bos. I, however, prefer to use the term Bovidce, 
somewhat in the latter sense, and to place the distinct types, as I have done below, 
in distinct genera. The reader can, if he prefers, of course consider the generic 
terms of the Bovidce employed here as being merely of sub-generic value, without 
interfering with the general scheme of the classification employed. 
ORDER UNGULATA : SECTION SELENODONTA ; DIVISION ARTIODACTYLA. 
Family : B Q VII) FE. 
Genus : BOS. 
The genus Bos may be defined from the characters of the cranium as follows : — 
Horn-cores placed immediately over the plane of the occiput ; occipital crest 
extending high up between the bases of the horn-cores, and the occiput generally 
squared, and with very slight lateral indentations of the temporal fossae : forehead 
flat or mesially ridged, longer than broad, and frontal longer than facial portion of 
cranium ; superior border of horn-cores at first convex ; in typical species the inter- 
cornual space is straight and the horn-cores are cylindrical; in some aberrant 
varieties the horn-cores are compressed, and the intercornual space is somewhat 
arcuated. 
It will be observed that the above definition differs in several points from those 
given by Hodgson^ and Gray^ ; these alterations have been rendered necessary by 
tlie new species now introduced into the genus. 
Bos NAMADicus, Fcilconer. Pis. 11 and 16, f. 1 & 3. 
Of the cranium of this, one of the best known species of the fossil Indian oxen, 
figures and an imperfect description have affeady appeared in the Journal of the 
Asiatic Society of Bengal {Vol. X, FI. F,figs. a, 6), and figures have also been given 
in the unpublished plates of the “Eauna Antiqua Sivalensis” {PI. G,Jigs. 1 a, b,c, 2 
' With the exception, perhaps, of Amphibos. 
^ Asiatic Society of Bengal, Vol. X, p. 452. 
® Catalogue of Ungulata in the British iliiseum. 
