10 
TEKTIAliY VEIiTEBRATA OF THE FAYCiM. 
rougliciicd. 'riic other alveoli are smaller, compressed from before backwards, 
and crowded together ; they arc separated by a very small space from the socket 
of i. 1 ill front and by none at all from that of the canine behind. The palatine 
portion of the jiremaxilloc is small : the premaxillo-maxillary suture runs backwards 
from immediately behind the alveolus of the last incisor, and the bones form little 
more of the palate than the high arched roof of the unpaired anterior palatine foramen, 
the ])osterior or ventral edge of which is formed by the anterior border of the palatine 
jilatcs of the maxillae. The facial portions of the premaxilhn form the very narrow 
Avedge-shaped extremity of the snout, the actual angle of wdiich is somewhat 
truncated and roughened. The suture wuth the maxilla (Pis. I., II., III.) runs upwards 
and backwards to a point midway between the nasal opening and the orbit ; and in 
front of this the bone unites Avith the nasal, the suture Avith Avhich runs just into the 
narial opening. Within the latter the premaxilla again meets the maxilla, forming a 
suture with the upAvard prolongation of that bone, which together Avith a doAvngrowth 
of the nasal forms a support for the large horns in the manner above described (see the 
description of the nasals and text-fig. 2). The posterior part of the border of the 
nasal opening formed by the premaxilla is rounded, but in front of this the bone is 
bent iiiAvards and doAviiAvards and terminates internally in an irregular roughened 
edge, the posterior angle of Avhich forms a blunt tuberosity. This inturned 
edge is separated from the corresponding portion of the bone of the opposite 
side by a deep groove (text-fig. 2, mes.g.), which in life probably lodged the loAV’er 
edge of a vertical cartilaginous nasal septum. In the young this remains unossified, 
but in the fully adult animal its anterior region ossifies and forms the prenasal bar 
of bone joining the nasals Avith the premaxillse, as above described (see Pis. I., II. 
fig. 1 a; also text-fig. 2). 
In consequence of the great size and the hypsodonty of the teeth, the maxilla (mx.) 
is very large. Its facial suture Avith the premaxilla has already been described, 
and it Avill be noticed that it is completely excluded from the margin of the 
nasal opening by the meeting of the premaxilla and the nasal. Within the 
nasal opening, hoAvev'er, it is produced upAvards into a process Avhich unites 
with a doAvngroAvth of the nasal in the manner already mentioned. Pehind its 
union Avith the premaxilla the upper border of the bone meets the frontal, and 
its suture Avith that bone terminates just behind the antorhitul foramen {a.of.), at 
Avhich point the small lachrymal is interposed, and helps to form the outer 
side of the bar of bone Avhich closes the antorbital foramen externally. 
This foramen is very large and opens by a Avide passage into the orbit. The 
maxilla is excluded from the actual margin of the orbit by the junction of the 
lachrymal Avith the upper end of the jugal, Avhich sends up a long process 
forming the Avhole ventral border of the orbit, and uniting anteriorly Avith the 
maxilla. The zygomatic process of the maxilla is very short, extending very little 
