ON THE BONES OF THE RHINOCEROS. 435 



ries him into climates so distant and so dangerous, solely for the ad- 

 vancement of science. These two valuable acquisitions afford the most 

 solid support to all this history of fossile rhinoceroses. 



I. Of the two-horned Rhinoceros of the Cape. 



Its skeleton is represented plate 54 ; its head, plate 42, figs. 6 and 7. 

 We have seen the principal differences of the head. - A minute exa- 

 mination still discovers some. 

 I. On the upper aspect. 



1 st. The horizontal contour of the bones of the nose is rounded in 

 the two-horned rhinoceros, pointed in the one-horned. A deep furrow 

 marks their suture anteriorly in the first. 



2nd. The space between the post-orbital processes is bunched out in 

 the two-horned animal, transversely concave in the one-horned. 



3rd. From this part to the occipital ridge, the cranium of the two- 

 horned rhinoceros appears much longer, because this ridge is directed 

 obliquely backwards, whilst it is vertical in the one-horned animal. 



4th. The temporal fossae approach less closely in the two-horned, 

 which leaves the upper and truncated part of the occipital ridge 

 broader. 



5th. The zygomatic arches are less asunder posteriorly, whilst in the 

 one-horned they form a salient angle; a circumstace which, joined to 

 the difference in the bones of the nose, causes the horizontal general 

 contour of the one-horned to be triangular, and that of the two-horned 

 to be oblong. 



II. In the profile, the principal differences are owing : 

 1st. To the form of the incisive bones, which in the one-horned ad- 

 vance as far as the bones of the nose, and have above a peculiar pro- 

 cess ; in the two-horned, they are reduced each to a small oblong 

 piece. 



2nd. To the convexity of the suborbital space of the two-horned, 

 already mentioned. 



3rd. To the elevation of the occipital ridge of the one-horned, and 

 to its flat position in the two-horned ; whence it happens that at an 

 equal distance between the occipital condyles and the muzzle, the one- 

 horned has the upper part of the cranium much shorter than the two- 

 horned. 



III. At. the lower aspect, besides the differences which arise from 

 the form of the arches, and the direction of the occipital ridge, and 

 that which is produced in front of the palate by the difference of the 

 incisive bones, we observe : — ■ 



1st. That the row of molar teeth is longer in the two-horned, and that 

 it converges anteriorly with that of the other side : in the one-horned 

 they are parallel. 



2nd. That the palatine fissure is pointed anteriorly in the two- 

 horned, rounded in the one-horned : in both it advances as far as the 

 penultimate molar tooth. 



3rd. That the basilar region is longer in the two-horned, so that we 

 find posteriorly, what had been lost anteriorly with respect to the 

 length. 



IV. The posterior aspect, semi-elliptical and more high than broad 



