18 MR. F, E. BEDDARD ON THE [Jan. 20, 
§. The Brain of CYNOPITHECUS NIGER. 
IT have been able to examine a single brain of the Celebesian Ape, 
of which drawings are exhibited herewith (text-figs. 7, 8, p. 19). 
The Simian fissure runs completely across and contributes to 
a perfect operculum, as in the Macaques. But the brain of Cyno- 
pithecus differs from the brains of the latter and agrees with that of 
Semnopithecus in the fact that the infraparietal fissure of each side 
bends sharply outwards before joining the Simian fissure ; this sug- 
gests an exposure of the parieto-occipital, and a very faint groove 
(better marked upon the left side) is probably to be looked upon 
as a representative of this. The lateral occipital sulcus is a single 
fissure, that is to say, it has not the Y-shape exhibited in so many 
monkeys. There is, however, a faint depression suggesting the 
upper arm of this ¥. The inferior occipital sulcus is in some respects 
rather peculiar. Dr. Elliot Smith has justly pointed out} that in 
Semnopithecus “the inferior occipital sulcus has dwindled to most 
insignificant proportions, and unless the student examines a large 
series of brains he will hardly recognize in the little arc around 
the lower end of the Simian sulcus the representative of the deep 
operculated infra-occipital suleus in the Macaques.” Cynopithecus 
niger has an even smaller semicircular representative of this 
furrow, which just arches round the lateral termination of the 
Simian fissure, and is nowhere near to reaching the posterior 
extremity of the occipital lobe. Further than this, a straight 
furrow, either connected (left side) or nearly connected (right 
side) with this, runs down the temporal lobe for some distance, 
exactly parallel with and between the parallel and collateral sulci. 
This I take to be the inferior temporal sulcus of brain anatomists. 
In the Macaques and Cercopitheci this sulcus is (so far as my 
own experience goes) quite constantly represented by a short 
furrow at the lower end of the temporal lobe, and this furrow is 
a marked character of those brains, and of Cercocebus and Cyno- 
cephalus. This more ventrally placed furrow is not to be seen in 
my specimen of Cynopithecus. The existence of an upper portion of 
the inferior temporal sulcus is not, however, absolutely distinctive 
of Cynopithecus. It is indicated in a brain of Cynocephalus 
mormon which I have at my disposal, and in Vasalis and Semno- 
pithecus. Ina brain of Cynocephalus porcarius this furrow is as 
well developed as in Cynopithecus, but on one side only (the 
right). But, with this exception, the furrow is nowhere so fully 
developed as in Cynopithecus. So far, therefore, it appears to be 
characteristic of this genus. It is, however, apparently impossible 
to lay much stress upon the reduced inferior occipital sulcus of 
Cynopithecus as a point of resemblance to Semnopithecus in the 
absence of a large series of brains of the former genus. Messrs. 
Kiikenthal and Ziehen figure a brain of Cynocephalus sphinx in 
which the fissure is fully as reduced as it is in Cynopithecus or 
Semnopithecus. I have already pointed out (supra, p. 12 foot- 
1 Cat. Phys. Series Mus. Roy. Coll. Surg. vol. ii. p. 426. 
