222 



Description of the Sivatherium, 



[July 



tion, like that in the corresponding tooth of the lower jaw. The plane 

 of grinding slopes from the outer margin inwards. The general form 

 is exactly that of an ox or camel, on a large scale. The ridges of 

 enamel are unequally in relief, and the hollows between them unequally 

 scooped. Each semi-cylinder has its outer surface, in horizontal section 

 formed of three salient knuckles,, with two intermediate sinuses ; and 

 its inner surface, of a simple arch or curve. But there are certain 

 peculiarities by which the teeth dflier from those of other ruminants. 

 Dimensions of the Teeth, 



Length. 



Inches. 



Last molar right, side, , 

 Penultimate do. 

 Antepenultimate do. 

 Last simple molar.. 



Second do. do 



First do. do 



2.20 



1.68 



1.55 



1.70 



, 1.70 



Outer 

 surfaces* 

 99 

 9.8 

 8.4 

 6.4 



Breadth. 

 Inches. 

 2.35 

 2.38 

 2 20 

 2.24 

 1.95 

 1.90 

 Inner 

 surfaces.. 

 5.5 

 4.5 

 4.5 

 3,2 



Interval between the surfaces of last molar 



do. do. do. third do 



do, do. do. second do 



do do. do. first do 



Space occupied by the line of molars 9.8 inches. 



The form and relative proportions of the jaw agree very closely with 

 those of the corresponding parts of a buffalo. The dimensions com- 

 pared with those of the buffalo and camel are thus : 



Depth of the jaw from the alveolus \ 



last molar ] 



Greatest thickness of do 



Width of middle of last molar. 

 Length of posterior |d of do 



Sivatherium. 

 4.95 inch. 



2.3 

 1.35 

 2,15 



Buffalo. 

 2.65 inch. 



1.05 

 0.64 

 0.95 



Camel. 

 2,70 inch. 



1.4 

 0,76 

 1.15 



No known ruminant, fossil or existing, has a jaw of such large size % 

 the average dimensions above given being more than double those of a 

 Buffalo, which measured in length of head 19.2 inches (.489 metres) ; 

 and exceeding those of the corresponding parts of the rhinoceros. We 

 have therefore no hesitation in referring the fragment to the Sivathe- 

 rium Giganteum. 



The above comprises all that we know regarding the osteology of the 

 head from an actual examination of the parts. We have not been so 

 fortunate hitherto, as to meet with any other remain, comprising the 

 anterior part of the muzzle either of the upper or lower jaw. We shall 

 now proceed to deduce the form of the deficient parts, and the struc- 

 ture of the head generally, to the extent that may be legitimately in- 

 f erred, from the data of which we are in possession, 



