46 The American Naturalist. [January, 
The general form of the skull is broad and depressed. Its dorsal con- 
tour is very like that of Paleotherium crassum,—namely, there is no 
frontal depression, which is so characteristic of Paleosyops paludosus, 
and the occipital region is only slightly higher than the frontal. 
temporal fossæ are not deeply excavated, and the occipital crests are 
weakly developed when compared to this region of the skull in 
Limnohyops. The occiput itself ishigh and rather narrow. The fora- 
men magnum is wide, bordered by very large condyles. The auditory 
processes are widely separated. The post-tympanics are broad and 
heavy. The post-glenoid is peculiar in form; it is very short and 
Pate@osyops megarhinus, sp. nov.; anterior and lateral view of skull; from the 
Washakie Eocene of Wyoming. 
thick ; its form is very different from other species in the collection. 
An internal glenoid process is present in this species, The mastoid was 
i obably exposed. The form of the zygomatic arch is striking ; it 5 
is very light, nearly straight, 
thin, and shelf-like. The infra-orbital foramen is not exposed. The form 
of the malar in this species is totally different from all other allied forms 
