on the Sivatherium giganteurti. 195 



Viewed in lateral profile, the form and direction of the horns, and the 

 rise and sweep in the bones of the nose, give a character to the head 

 widely differing from that of any other animal. The nose looks something 

 like that of the rhinoceros ; but the resemblance is deceptive, and only 

 owing to the muzzle being truncated. Seen from in front, the head is 

 somewhat wedge-shaped, the greatest width being at the vertex and thence 

 gradually compressed towards the muzzle ; with contraction only at two 

 points behind the orbits and under the molars. The zygomatic arches are 

 almost concealed and nowise prominent : the brow is broad, and flat, and 

 swelling laterally into two convexities; the orbits are wide apart, and have 

 the appearance of being thrown far forward, from the great production of 

 the frontal upwards. There are no crest or ridges : the surface of the 

 cranium is smooth, the lines are in curves, with no angularity. From the 

 vertex to the root of the nose, the plane of the brow is in a straight line, 

 with a slight rise between the horns. The accompanying drawings will at 

 once give a better idea of the form than any description. 



Now in detail of individual parts ; and to commence with the most im- 

 portant anil characteristic, the teeth* : 



There are six molars on either side of the upper jaw. The third of the 

 series, or last milk molar, has given place to the corresponding permanent 

 tooth, the detrition of which and of the last molar is well advanced, and 

 indicates the animal to have been more than adult. 



The teeth are in every respect those of a ruminant, with some slight in- 

 dividual peculiarities. 



The three posterior or double mclars are composed of two portions or 

 semicylinders, each of which incloses, when partially worn down, a double 

 crescent of enamel, the convexity of which is turned inwards. The last 

 molar, as is normal in ruminants, has no additional complication, 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 re- 

 lief, and the hollows between them unequally scooped. Each semicylinder 

 has its outer surface, in horizontal section, formed of three salient knuckles, 

 with two intermediate sinuses j and its inner surface, of a simple arch or 

 curve. But there are certain peculiarities by which the teeth differ from 

 those of other ruminants. 



In correspondence with the shortness of jaw, the width of the teeth is 

 much greater in proportion to the length than is usual in the family : the 

 width of the third and fourth molars being to the length as 2'24 and 2-2 

 to 1*55 and 1'68 inches, respectively; and the average width of the whole 

 series being to the length as 2-13 to 176 inches. Their form is less pris- 

 matic: the base of the shaft swelling out into a bulge or collar, from which 

 the inner surface slopes outward as it rises : so that the coronal becomes 

 somewhat contracted : in the third molar, the width at the coronal is 1-93, 

 at the bulge of the shaft 2-24. The ridges and hollows on the outer sur- 

 face descend less upon the shaft, and disappear upon the bulge. There 

 are no accessory pillars on the furrow of junction at the inner side. The 

 crescentic plates of enamel have a character which distinguishes them 

 from all known ruminants : the inner crescent, instead of sweeping in a 

 nearly simple curve, runs zig-zag-wise in large sinuous flexures, somewhat 

 resembling the form in the EInsmotherkmi. 



The three double molars difler from each other only in their relative 

 states of wearing. The antepenultimate, being most worn, has the cre- 

 scentic plates less curved, more approximate and less distinct : the penulti- 

 mate and last molars are less worn, and have the markings more distinct. 



• The figure of the palate and teeth in the Engraving is on rather a larger 

 scale than the rcst.'^EmT. Asiat. IIes. 

 Y2 



