158 THE ANATOMY OF THE BINTURONG. 
having the posterior and not the anterior of the limbs of the internal 
circumsylvian gyrus of greater breadth. 
Fig. 4. 
Brain of the Binturong. 
The Sylvian fissure tends to be vertical, but is directed somewhat 
backwards as well as upwards. It is surrounded by three gyri. The 
inner commences behind, near the lower border of the temporal lobe, 
and, after ascending as high as the top of the fissure, bends round it 
and descends on the frontal lobe to the supraorbital fissure, when it 
again doubles forwards to form the commencement of the middle 
gyrus. Its posterior limb is twice the breadth of the anterior, and is 
bisected by a vertical fissure which extends down as far as the hori- 
zontal temporal fissure. The middle gyrus is of uniform breadth 
throughout, and, commencing at the folding of the inner gyrus on the 
frontal lobe, goes round it and terminates at the lower border of the 
temporal lobe behind; there is no fold in it at its posterior superior 
angle. The third or outer gyrus is but slightly bent in its anterior 
Page 202. limb, which commences at the supraorbital fissure; it embraces 
the middle gyrus, and does not cease opposite its posterior superior 
angle, but descends about halfway down iis posterior limb to end by 
a point. 
The whole brain narrows in front; and the crucial sulcus is not at 
all strongly marked. The corpora albicantia are separated behind ; 
and the optic nerves in front of the chiasma run forwards close to- 
gether. The pituitary body is of fair size. 
