THE SKULL OF PALEORHINUS 125 
narial region is marked by small irregular pits and elevations, while 
the snout is rather smooth, with ornamentation about like that of the 
lateral portions of the skull. 
Premaxilla.—The premaxilla is greatly elongated and makes up 
the entire rostrum except that portion immediately surrounding the 
nares. This part of the skull is, however, so shattered that the sut- 
ural relations of premaxilla, maxilla, and nasal cannot be determined 
with accuracy. Judging from von Meyer’s figures of Belodon the 
premaxilla should extend to within about two inches of the nares, 
while the maxilla extends forward about two inches under the pre- 
maxilla. The indications point to this being the case. If this is 
true it gives the premaxilla a length of about fourteen and one-half 
inches. 
The two premaxilla were never fused; the suture remained dis- 
tinct throughout life, and the union of the bones was so slight that 
the post-mortem crushing of the skull has caused them to slip over 
one another for almost one-half inch in one place. 
Masxilla.—There seems to be a suture extending from a little in 
front of the middle of the upper border of the preorbital vacuity 
forward and slightly upward till it reaches a point opposite the middle 
of the naris, whence it descends rapidly, about parallel with the upper 
line of the snout, until it reaches the margin of the jaw about six 
inches in front of the point of its origin. This would be the union 
between the maxilla and the nasal for about four. inches and between 
the maxilla and premaxilla for the anterior two inches. How far the 
maxilla extends backward and where it unites with the jugal cannot 
be positively stated, though by analogy with the European forms 
the union should be on that part of the cheek between the antorbital 
and lateral temporal vacuities. The maxilla lies below the lachrymal 
behind the antorbital opening and is united with that element for 
about two inches. Here it probably meets the jugal—about under 
the middle of the orbit. This would give to the bone a length of 
between eleven and twelve inches. 
Nasals.—The nasals are also quite large bones. They extend 
from the premaxille backward about four inches posterior to the 
nares, which they entirely surround and which they separate by 
means of thin vertical septa, which pass downward for some dis- 
tance in the median plane, how far is not determined, but since one 
