ON GELADA RUEPPELLI. 511 
Surrounding the upper end of this last sulcus, but not meeting it, 
is one whose posterior limb (c, c) forms the anterior boundary of the 
occipital lobe, the posterior transverse fissure, whilst its anterior limb 
(g, g) rans forwards, downwards, and outwards, to end independently 
as in allied Primates. Where these two limbs meet a small sulcus 
runs inwards to the middle line, becoming conspicuous on the median 
; aspect of the hemisphere. 
: The prolongation upwards and backwards of the Sylvian fissure 
on the outer surface of the brain meets the major oblique temporo- 
parietal sulcus as above mentioned. Whether or not it should meet 
it is uncertain in allied species of the same genus according to 
; Gratiolet. It is peculiar, however, in that from a little above and 
below its middle it sends forward small branches (e, e and n,7”). In 
the Cynocephali alone is anything of this kind seen, and in them the Page 457. 
lower of these two sulci only (x, x). 
The anterior transverse (parietal) fissure (d, d) commences ex- 
ternally between the two small sulci just described (e,e and n,n), 
After running forward and upward it bends, turning slightly back- 
: wards to the middle line, where it ts continued downwards upon the 
median surface of the hemisphere for a short distance, as in no species 
described by Gratiolet. 
The three-way convolution of the frontal lobe (fff) resembles 
that in the Cynocephali—the Semnopitheci, Macaci, and Cercopithect 
- almost or entirely lacking its posterior limb, which is well represented 
in the Geladas and Baboons. 
Small independent sulci are more numerous than in Macacus and 
} Cercopithecus—about as many as in the Oynocephali, with which the 
’ Gelada most agrees in size. 
Correlation of the facts above recorded makes me place Gelada 
along with Cercopithecus and Cynocephalus away from Macacus. Its 
affinities with Cercopithecus seem to me more intimate than with 
Cynocephalus, to which genus it most certainly does not belong. 
NS 
—e ba 
EXPLANATION OF PLATE 31. (XXXVIIL) 
Brain of Gelada rueppelli, natural size. 
Fig. . Right hemisphere, outer aspect. 
Pe 9 inner aspect. 
= % 3 superior aspect. 
4. 7 - inferior aspect. 
Ps a 
en 
sina 
