14 MR. F. E. BEDDARD ON THE [Jan. 20, 
of the present communication, while the internal view of one 
hemisphere is shown in another drawing (text-fig. 4, p. 15). The 
variations that I have noted in the three brains are the 
following :— 
There is some variability in the exposure on the upper surface 
of the brain of the parieto-occipital fissure. This, as will be seen 
from the drawing exhibited (text-fig. 2, p. 13), is better marked in 
a large female brain, given to me by Dr. Hose, than in the smaller 
male brain (text-fig. 3, p. 13). In the third brain there are only 
just traces to be observed of this fissure on the superficial view of 
the brain. A furrow which I identify with the postcentralis 
superior is present here in rudiment (as it is in the Macaques and 
other genera) occasionally. It is best developed, but practically 
on one side only (the right), in the small male which lived in the 
Society's Gardens. In the large female brain there are traces 
of the fissure on one side only (the right); the fissure is absent 
in the third brain. 
The fissure of Rolando curves back and joins the Sylvian 
fissure In the large female brain; it does not do so in the two 
remaining brains. On the left side of one brain the Sylvian and 
the parallel fissures joined superiorly, a state of affairs which is 
characteristic of the brains of many monkeys. 
On the right hemisphere of one brain only the lateral occipital 
fissure was Incomplete, and consisted of the lower arm only, there 
being but a faint indication of the upper arm of this Y-shaped 
fissure. 
These appear to me to be the principal differences in the sulci 
of the three brains. 
I have compared them carefully with the brains of six species 
of Semnopithecus ', of which I owe two to the kindness of Dr. Hose, 
while four were extracted from the skulls of specimens which 
have lived in the Society’s Gardens. 
The species are as follows:—S. maurus, S. femoralis, S. hypo- 
leucus, S. rubicundus, S. priamus, and S. entellus. The differences 
between these brains and those described by Kiikenthal and 
Ziehen ° are slight. 
The fissure lettered H by the above-named authors, which is 
the presylvian of other writers, is less regular in its occurrence 
than it appears to be in Vasahs, but the difference is not sufficiently 
marked to permit of any stress being laid upon the fact. In onl 
one instance (S. femoralis), and on one side only (the right), did 
the Sylvian fissure join the parallel fissure above. The rarity 
of this arrangement is exactly as in Vasalis. In one case only 
(S. maurus), and also on one side only (the left), were there 
indications of the fissure of Rolando joing the Sylvian fissure. 
The rarity of this arrangement is again paralleled in Vasalis. 
1 Kiikenthal and Zichen (Jen. Zeitschr. 1895, p. 1) refer to the literature, but they 
have not included a paper by Lankester (Quart. Journ. Sci. ii. 1865). 
2 “ Untersuchungen tiber die Grosshirnfurchen der Primaten,” Jen. Zeitschr. 1895, 
p. 1. 
