GO 
EOCENE CROCODILIA. 
descent of the superior surface to the margins. The latter are acute and 
not produced nor recurved. This evidently pertained to an animal much 
more robust than the others, and of smaller size. 
Measurements. . 
M. 
Length of the postabdominal from the transverse line of the end of the dermal 
suture. .-...... 0. 060 
Thickness at the middle.... . 0.027 
CROCODILIA. 
DIPLOCYNODUS, Pomel. 
This genus, which is abundantly represented in the Tertiaries of 
France, was first detected by me in the Bridger basin of Wyoming, where 
a single species, the D. subulatus, occurs. A second species was found in 
New Mexico by the writer, which presents typical characters in the paired 
canine teeth and broad, overhanging muzzle, in which the nasal bones do 
not divide the external nares. In one of the specimens, numerous dermal 
bones are preserved, and they are withotit keels. 
Diplocynodus sphenops, Cope. 
Plate xxix. 
System. Cat. Vert. Eocene New Mexico, U. S. Geog. Survs. W. of 100th M., 1875, p. 31. 
Indicated by a fragmentary skeleton, in which occur numerous portions 
of the cranium and vertebrae; a second specimen includes corresponding 
parts, with more numerous vertebrae. In both, the distal part of the man¬ 
dibular ramus is preserved, and shows two enlarged teeth inserted close 
together, the posterior opposite to the posterior border of the symphysis. 
In front of these, there is an edentulous space; behind them is a series of 
quite small teeth. The dentary bone is quite narrow at this point, indicating 
an acuminate symphysis and muzzle. 
The type-specimen includes the frontal and parietal bones. The 
former united are not expanded, but are about as wide as in Crocodilus 
eUiottii, Leidy. The interparietal face is a plane, is narrow, its sharply defined, 
lateral borders including two rows of deep pits. The front is rough, with 
deep pits, which have a transverse direction opposite the postfrontal bones; 
