AGRIOCHOERUS. 25 
straight line from the posterior part of the orbit to the most anterior of the molars 
in the specimen. Viewed laterally (Fig. 5), it is remarkable for the lowness of the 
forehead and the parallelism of its upper part with the alveolar margin. 
The forehead is broad, and between the anterior part of the orbits is convex, but 
between the posterior part, at its middle half, is flat or slightly depressed, and upon 
the post-orbitar processes is rather abruptly depressed. 
The posterior part of the os frontis, in the specimen, has a small fragment of the 
ossa parietalia attached on each side, and between these it is convergent backward 
to where it is broken off, evidently indicating it to have been pointed and received 
into a notch of the parietalia as in the Camel and Merycopotamus. Anteriorly, 
the os frontis, though broken, is easily perceived to have terminated in angular 
processes between the ossa lachrymalia and nasi. 
The remains of the frontal suture existing in the specimen, are distinct and zig- 
zag posteriorly, but straight and a little out of the normal course anteriorly. 
About a line on each side of the frontal suture, in a position corresponding to 
the anterior third of the orbit and ten lines from its margin, is a small supra-orbitar 
foramen. 
No portions of the nasal bones are preserved, and the notch of the os frontis, for 
the reception of their posterior extremity, is too much broken to ascertain their 
limits in this direction, but they appear to have extended a little posterior to the 
position of the anterior orbital margin. 
The orbital entrance is open posteriorly as in Anoplotherium, but is relatively 
larger than in this, and its plane is directed outward and as much upward almost 
as in feline animals; but not so much forward as in the Deer, though rather more 
so than in the Musks. In form it is subcircular, and is about one inch in diameter. 
The post-orbital processes of the os frontis and os mals are six lines and three- 
fourths distant from each other, and are thick, compressed, conoidal, and pointed. 
That of the former bone is directed outward and downward, that of the latter 
upward, inward, and slightly anterior, and its point is about four lines external 
to the one above. 
The lachrymal margin is partially broken, but it appears to have been only 
slightly prominent. The facial surface of the lachrymal bone is seven and a 
half lines in vertical diameter, and is a feebly depressed inclined plane, on the 
same level nearly as the orbital entrance. 
The malar bone, compared with that of recent ruminants, is robust, and its 
external face, below the orbit, is vertically slightly convex. Antero-posteriorly it 
is convex, and its anterior limit is on a line with the first true molar tooth. 
The superior maxillary bone, from the position of the malar bone forward and 
upward, as far as it is preserved in the specimen, is prominent and convex, and 
below this upon the alveoli is vertically convex. The infra-orbitar foramen - is 
vertically oval and directed forward, and is situated above the hinder fang of the 
penultimate premolar an inch in advance of the orbit. 
The hard palate, for the most part, is obscured by a very hard matrix, to remove 
which would endanger the specimen; but where exposed, between the anterior of 
the premolars, it is remarkable on account of the very great degree of inclination 
