NEWER PLIOCENE BEDS IN BRITAIN. 281 
The bases of the two horn-cores were not set parallel upon the skull, 
but diverged posteriorly. It is evident that the skull was very 
narrow, a space of not more than from 14 to 16 millim. intervening 
between the bases of the two horn-cores ; and the orbits must have 
very nearly met below the brain. The pedicle extends downwards 
in front of the orbit, and towards the middle line the frontal bone 
recedes, so as to form a hollow forehead. Close to the frontal 
suture the bone thickens again, so that when the two frontals were 
together, there must have been a median ridge. On the front and 
inner side of the pedicle, quite at its lower extremity, a deep trian- 
gular depression, or fossa, is seen (fig. 2, ff.), from the upper part of 
which a large foramen pierces the frontal bone and passes directly 
into the upper and inner side of the orbit. Above and behind the 
orbit there is a well-marked pit, which indents the hinder fourth of 
the pedicle (fig. 1, pp.). No air-cavities can be seen in the frontal 
bone, and indeed the inner and outer tabule are so near together as 
to render it probable that only cancellated bone intervenes between 
them. 
Measurements in Millimetres. 
Height of horn-core from margin of orbit........ 84:0 
Antero-posterior diameter of ditto at base........ 33'D 
Lateral a Pe res Pose 5 21°5 
ieKobable diameter of orbit... 7.2... ck wk ec 31:0 
Greatest width of specimen from frontal suture 35.0) 
to the present outermost part of orbit...... 
Wiemeter ot frontal foramen ............5..... 45 
The frontal bone being almost perfect and having the impressions 
of the cerebral convolutions preserved on its inner surface, it has 
been possible to take a plaster cast, which reproduces the form of the 
right frontal lobe and shows clearly the characters of its convolu- 
tions, thus enabling us to compare these important parts with those 
of the recent Antelopes. The remarkable compression of the brain 
in the orbital region is one of its most marked characters. ‘The outer 
side of the frontal lobe, which rested upon the orbital plate, is almost 
plane (fig. 5), but two longitudinal sulci are traceable. The upper one 
is the more distinct, and towards the front it curves upwards and 
ends in a depression ; posteriorly it deepens, and, passing upwards, 
forms the Sylvian fissure (sf.). Viewed from above (fig. 4), one 
convolution (a) is seen to follow the contour of the outer edge. 
This convolution at its hinder part is pushed upwards by the 
Sylvian fissure (sf.). More towards the middle line are two other 
convolutions of a sigmoid form (6,¢), or rather one broad one with 
a sulcus along its middle incompletely dividing it into two parts. 
- On the inner side of the hinder end of the last-mentioned convo- 
lution is a portion of another one (d), small but deeply curved. In 
front of this, and next the middle line, is a roughened space, probably 
indicating another convolution (¢), the somewhat enlarged termination 
of which (¢) is seen at the front of the brain just above the olfactory 
lobe, the position of which is shown in fig. 5, of. 
