1X COR VYPHODON ZOV, 
by Professor Marsh ; the numerous points in common possessed 
by the members of both families forbid their separation more 
widely than as families. 
The earliest types of Amblypoda belong to the genus 
Pantolambda, of which the species P. bathmodon was about four 
feet in length. As restored it seems to have had proportionately 
short fore- and hind-lmbs, and it had a long tail. It was 
apparently plantigrade, and would have had not a little hkeness 
to a carnivorous type. The skull has no air cavities, such as are 
developed in the later types from the Lower Eocene, e.g. Cory- 
phodon ; Pantolambda is from the basal Eocene. The frontal 
bones show no trace of the horns that are developed in subsequent 
forms; the nasals are comparatively long; the zygomatic arch is 
slender. The molar teeth are in the primitive form of trituberculy, 
and the premolars, as is so often the case with primitive animals, 
are unlike the molars in form, being less markedly selenodont. 
As to the vertebral column, the dorsal vertebrae appear to have 
had short spines, which argues, as it does also in the case of the 
larger and heavier Coryphodon, a feebleness in the development of 
ligaments and muscles supporting and moving the head. The 
scapula seems to have the same peculiar leaf-like form that it has 
in the later Coryphodon.' This primitive type shows an entepi- 
condylar foramen in the humerus. It is interesting to observe 
that the posterior border of the ulna is convex, as in the Creodonts, 
and in the early Condylarthrous form Huprotogonia. In the sub- 
sequently-developed Amblypoda, as in the later Condylarthra, 
that bone acquires a concave outer border. In the carpus the os 
centrale is distinct. In the femur the third trochanter is well 
formed; it gradually dies out in later Amblypoda. The fibula 
articulates with the calcaneum. ‘This species, according to Osborn, 
“typifies the hypothetical Protungulate, being more primitive 
than either Huprotogonia or Phenacodus.” ” 
The genus Coryphodon is known by a large number of species, 
of which the first was discovered in this country, and was repre- 
sented merely by a jaw with some teeth. This was named by Sir 
R. Owen CT eocaenus, and was dredged up from the bottom of the 
sea off the Essex coast. A second specimen consisted of a single 
1 The scapula of P. bathmodon is unknown. 
* For the structure of this genus and of Coryphodon, see Osborn, Bull. Amer. 
Mus. Nat. Hist. x. 1898, p. 169. 
