98 



R. S. Lull — New Tertiary Artio dactyls. 



KSL 180 female 

 Young male Adult 

 milk dent, worn dent. 



Antilocapra 



ESL 



Young Ratio 



female 10744 



milk dent, and 180 



m. m. m. 



Length over all -2840 -2860 -2550 



Width of brain case -0700 -0720 -0730 



Maximum width (zygoma) -1300 -1280 -1250 



Height ant. to orbit -0650 -0700 -0634 



Vert. diam. of orbit -0400 0436 -0400 



Occipital height -0575 -0570 -0565 



Occipital width -0825 -0790 -0763 



Width of palate at P 2 -0350 -0305 -0310 



Width of palate at M 3 0485 0520 -0485 



m. 

 1-68 

 1-50 

 1-60 

 2-00 

 1-61 

 1-63 

 1-88 

 1-17 

 1-45 



Av. 1-61 



Brain. — A very excellent natural cast of the interior of 

 the cranium of Aletomeryx exists (Cat. No. ^ ), lack- 

 ing only the olfactory bulbs and certain details of 

 the inferior aspect. Another specimen, however (Cat. 

 No. ^ 5 ), consisting of a cranial floor containing a resi- 

 due of matrix, was cleared and a wax impression 

 taken of its. interior. This gave additional data, so that 

 we are lacking only the olfactory bulbs and optic nerves, 

 and these have been restored in the drawings (fig. 6). 

 The endocranial cast differs of course from the brain 

 itself in that it is a replica of the dura mater and not of 

 the cortical surface, hence the fissures are neither so 

 numerous nor so well-defined as they would be in the 

 actual brain. Furthermore, the imprint of the inner 

 surface of the petrous bone, which is so striking a feature 

 of the cast, is lacking on the brain itself. Nevertheless, 

 the relative proportions of parts are clearly shown, al- 

 though in the inferior aspect (iig. 6C), instead of 

 cranial nerves one sees the impressions of the several 

 foramina which transmitted them. 



The brain is of considerable size, as the figures, which 

 are in their natural dimensions, show, but varies some- 

 what in proportions as compared, for instance, with that 

 of the ox, in that the portion below the rhinal fissure is 

 relatively larger and the cerebral portion above propor- 

 tionately less, a more primitive condition in the fossil. 

 The hinder portion of the cerebrum is of ample width as 

 compared with the prefrontal area, showing a relatively 

 high development of muscular control as compared with 

 intelligence. The centers of hearing and sight are also 



