. 5 
1877.) 51 pene: 
slightly defined convolutions, the best marked being inferior and sub- 
round in form. 
The cerebral hemispheres, viewed from above, have an oval outline, and 
are rather narrower anteriorly than posteriorly. They contract posteriorly 
from the sylvian convolution. The profile descends gradually to the olfac- 
tory lobes. The superior surface is little convex in the transverse direc- 
tion. The fissure of Silvius is nearly vertical in position, and its superior 
extremity is visible from above. A strongly marked fissure extends poste- 
riorly from it, defining the lobus hippocampi above. The sylvian convolution 
the thickest of all, and its outer border is emarginate in front and behind; 
below the postero-superior emargination it is thickest and most protuber- 
ant. Between it and the position of the falx there are three longitudinal 
convolutions, the external, the median, and the internal. These are slight- 
ly divergent posteriorly, but the posterior extremities of those of une side 
tend to unite on the posterior border of the hemisphere. Their surfaces 
aresmooth. The external is widest medially ; and it terminates anteriorly 
just behind the apex ef the sylvian convolution. The internal is double 
posteriorly ; the median is simple, and unites with the internal above the 
apex of the sylvian convolution. The two conjoined continue for a short 
distance and terminate in a broad tuberosity. Below the external con- 
volution on the side of the posterior part of the hemisphere there are four 
smal] longitudinal convolutions. The orbital portion of the hemispheres 
is extensive, and nearly smooth from the olfactory lobes to the supra- 
orbital border. This is not prominent, but is represented by a short longi- 
tudinal ridge. Above each of these, on the superior or front aspect of the 
hemispheres, is a massive convolution bent crescent-shaped, with the con- 
vexity inwards. The posterior part of the convolution is a sub-round 
tuberosity which stands opposite to. and in front of, the furrow separating 
the sylvian and median convolutions. The middle part of the crescent is 
less prominent, but the anterior extremity forms another tuberosity whose 
long axis is cirected downwards and outwards. The crescentic convolu- 
tion of the one side is separated from that of the other by a wide, shallow, 
median longitudinal groove, which extends transversely at the posterior 
tuberosities. The two tuberosities and the olfactory lobes form three de- 
scending steps. 
As compared with the brains of the existing Bovide that of the Procamelus 
differs in the forms of the cerebellum and medulla oblongata as already 
pointed out. The hemispheres differ in being shorter behind and more 
depressed in front. The convolutions of the posterior region are the same 
in number as in the sheep, but are less undulating in their outlines ; but 
there is a marked difference in the anterior convolutions. The median 
convolutions do not, as in the sheep, extend to the extremity of the anterior 
lobe, but terminate above the sy]vian fissure, so that there only remain in 
front of them the two large supraorbital convolutions, instead of the four 
common to existing Bovide and Cervide.* In this respect it more nearly 
*See Leuret et Gratiolet Anatomie comparée du Systeme Nerveux, 1839-57, 
Atlas, pls. vii-x. 
