1884.] The Amblypoda. 1193 
Bathmodon is nearest to the genus Pantolambda in its foot struc- 
ture. The astragalus has the same subquadrate outline (compare 
Figs. 3d and 19 a), and possesses, as in that genus, a facet on 
its internal anterior angle, for another bone. This character 
is found among recent Mammalia in certain rodents, where a 
separate bone, the internal navicular, articulates with the internal 
extremity of the astragalus. This is probably the case in Bath- 
modon and Pantolambda, but the separate bone has not been 
found. In Coryphodon it is evidently wanting, as the astragalus 
terminates internally in a hook-like apex, which gives it a very 
peculiar appearance (Fig. 2). Until I traced this astragalus to 
Coryphodon in 1873,) the relation of this genus to the Dinocerata 
had not been suspected. 
i If of the 
pti pa ee than Core see te tan cas on 
natural size. From Wasatch bed of New Mexico. Original. 
The small size of the brain in this family is well displayed in 
the section of the skull of Coryphodon represented in Fig. 12, 
where the cavity it has occupied is exposed. Its relations to the 
ull are entirely different from those observed in at feet 
Mammalia excepting the elephants. As in them the diploë 1s 
represented by large air chambers. Fi 
The characters of the brain itself may be learned from ig. 
13. The exceedingly small size of the cerebral hemispheres 
at once arrests the attention, being much smaller than in the 
1 
: ings Amer. 
“On the short-footed Ungulates of the Eocene of Wyoming. Proceedings 
‘soph. Society, 
