SIVATHERIUM GIGANTEUM. 267 



hollow, and the suture, as in the Bovidce, appears to have 

 been lower than the crest. 



The mastoid regions on both sides are of great width, equal- 

 ling that of the space across the two condyles. The frontal, 

 as before mentioned, is contracted between the rear and front 

 horns, and is depressed slightly in the interval between them, 

 from which it swells on either side in a bulge which runs into 

 the base of the horns. The base of the left rear horn is only 

 present in part. The right one shoots out laterally and back- 

 wards, and slightly upwards, as in the Bovidce, and from the 

 rear portion of the frontal, where it meets the plane of the 

 occipital exactly as in the Bos. It overhangs the temporal 

 fossa, and the fossa has the same form exactly as in the Bovidce. 

 The pedicle for the first 4^ inches of its rise from the swell of 

 the brow is contracted ; it then expands with a hollow and a 

 flattish edge both posteriorly and anteriorly, its vertical 

 diameter being 3"3 while its longitude is 6*68 at the contrac- 

 tion, but at the expansion it is 7f . The horn now presents 

 the extraordinary appearance of trifurcating, one main branch 

 composing the greatest portion of the diameter of the horn, 

 being given out from the centre and proceeding laterally and 

 upwards. It has a central hollow core of about 2 inches 

 diameter and walls of about an inch in thickness. The posterior 

 branch, which is broken off at its base, is sent off at right 

 angles to the central one, and nearly in the same plane. It 

 has no hollow core, but is cancellated throughout, like the 

 articulating heads of the bones of the extremities. It aj)pears 

 to have proceeded directly backwards, and to have been much 

 smaller than the central one. The hollow core of the central 

 branch is incomplete at its outer and lower side, having no 

 cincture of bone here, but jouas on with an oblong produc- 

 tion of hollow proceeding downwards and outwards. This 

 lower branch at its anterior and lower side is surrounded by 

 a cancellated paries of bone, which is sharp and flattened for- 

 wards and nearly two inches in thickness. This appears to 

 have been the centre of a third branch or off-set from the 

 common pedicle proceeding directly outwards. The anterior 

 or front horn is broken off close to the base, which is hollow, 

 and with an appearance of large cells from the parietes of it. 



]S"ow what was the character of the horns? Were they 

 cores of hollow horns as in the Bovidce ? — or branched antlers 

 as in the Cervidce ? — or were the front the former, and the rear 

 the latter ? About the front ones there can be no doubt. 

 They are conical, rise rapidly to a point, are smooth, have 

 no burr, are hollow at their base, and are formed of large 

 cells throughout: no ruminant had ever antlered horns 

 of this sort. They miist, therefore, have been cavicorned 



