ARTICLE VIL. 
REMARKS ON SAUROCEPHALUS AND ITS ALLIES. 
BY JOSEPH LEIDY, M.D. 
[Read November 21, 1856.] 
Tuer genus Sawrocephalus was founded by Dr. Harlan on a specimen consisting of the 
greater portion of the right upper maxillary bone with teeth of a sphyreenoid fish, dis- 
covered in a cavern on the Missouri River, and which probably belonged to the cretaceous 
period. The animal was supposed by Dr. Harlan to have been a saurian, and to the ‘spe- 
cies he gave the name of S. lanciformis. 
A second and much smaller species was subsequently described by Dr. Hays under the 
name of Sawrodon Leanus, from a specimen consisting of the upper and lower jaws, ob- 
tained from the green sand of New Jersey, and now in the possession of Dr. Isaac Lea, who 
has kindly loaned it to me for inspection. Dr. Hays was aware that the animal indicated 
by this specimen belonged to the same genus as the species described by Dr. Harlan with 
the name of Saurocephalus lanciformis, but conceiving the generic name not appropriate, 
changed it to that of Sawrodon.  - 
In both species the superior maxillary bone is a trapezoidal plate a little convex exter- 
nally and concave internally. Its two longer borders are the dental border, and the upper 
one, which is directed backward and downward, and externally is jagged as if for sutural 
connexion with other bones. The posterior border is also jagged, yet it is too imperfect 
in the specimens to judge accurately of its natural condition. The anterior border is 
longer than that just indicated, and in the specimen of Saurocephalus Leanus is united by 
suture with the premaxillary bone. (Pl. VI. fig. 8, 12 a.) 
The number of teeth occupying the maxillary bone of S. Leanus (fig. 12 a,) appears to 
be thirty-six, but in 8. lanciformis, (fig. 8,) so far as can be judged from the imperfect spe- 
cimen under consideration, the number appears to have been eight or ten less. 
