ON TULYPEUTES TRICINCTUS. 437 
Rapp,* being comparatively simple in its gyration. There is not 
that difference in the breadth of the anterior and posterior portions of 
the cerebral hemispheres which is found in Dasypus sexcinctus. 
The Sylvian fissure is only represented by an open and very shallow 
angle, above which, on the surface of the hemisphere, is a slight, partly 
encircling, shallow groove of some length, separated from it by a very 
short distance (vide fig. 2, ¢). 
Fig. 2. 
“ Brain of Tolypeutes tricinctus. 
The large olfactory lobes are much broader than they are deep. 
On the surface of each cerebral hemisphere there are two sulci. 
One of these, the anterior, is horizontal, and divides the frontal lobe 
into an upper and a lower part. Its outer extension is nearly to the 
lateral margin, not going backwards more than one fifth the length of 
the hemisphere. Internally it ceases on the flat interhemispheral sur- 
face as far backward as its outer end (vide fig. 2, a). 
The second sulcus is upon the superior cerebral surface, running from 
behind forwards and inwards. Posteriorly it commences at the outer 
posterior angle of the hemisphere a short distance from its extremity. Page 227. 
It does not, therefore, turn round the posterior end of the hemisphere 
to become continuous with the fissure of the hippocampus, as it does 
in Dasypus sexcinctus. Anteriorly it ceases in the middle of the 
superior surface of the frontal lobe, a short distance behind the con- 
vex margin of its upper moiety, and at about the transverse level of 
the ends of the anterior sulcus. The general direction of this sulcus 
is horizontal when viewed from the side, it being slightly curved, with 
its convexity downwards. 
* “Edentaten,” tab. viii. fig. 3. 
