402 O. C. Marsh—Notice of new Tertiary Mammals. 
EKohippus pernia, sp. nov. 
A smaller species of the same genus is indicated by frag- 
mentary remains of several individuals. Most of these fossils 
are in excellent preservation, and among them are some of the 
most characteristic portions of the skeleton. The distal end of 
the tibia is remarkably like that of the modern horse. The 
astragalus, also, is quite equine in type, but the anterior por- 
tion is more elongated. It has a small facet for the cuboid, as 
in the horse. The molar teeth are similar in pattern to those 
of Orohippus. 
The following are some of the principal measurements: 
Extent of three lower true molars. -_------ .----------- 20+: Ph 
Antero-posterior diameter of first lower true molar_..---- 6 
) revere diameter... . 2.6 os25 oso oe 5 
Depth of lower jaw below first true molar ----..------- 11 
Antero-posterior diameter of distal end of tibia ---- ---.-13° 
Transverse diameter -__.._----. pe eo 2 
ieéneth of aptrapalas <. 2. 005 coc vs coches ee 15°5 
Transverse diameter in front .__. ---- - EP en. 
Parahyus vagus, gen. et sp. nov. 
An interesting genus of suilline mammals is represented by 
a nearly perfect lower jaw and a few other remains in the Yale 
Museum. This jaw, which has most of the teeth well pre 
served, shows a near affinity to Elotherium Pomel, and to 
Helohyus Marsh, but it may easily be separated from those 
genera, as it has one less premolar. It differs from the former 
genus, moreover, in its last lower molar, which has a We 
developed posterior lobe. In other respects, the teeth are very 
similar to those of Hlotherium. The present genus affords 7 
interesting example of an extinct form outside of the ancestra 
line which terminated in existing suillines. A similar exam 
ple is seen in Anoplotherium. ' h 
The specimens preserved pertained to an animal about th 
size of a modern wild boar, but the jaws were proportionately 
shorter and stouter. The canine was large, and the three pre 
molars were all compressed, and each had two roots. 
e dimensions of this specimen are as follows: 
Extent of six molar teeth _..._._.._..-.------------"" vt 
Antero-posterior diameter of last lower molar----------- 
Transverse diameter___. __ 
Antero-posterior diameter of first true molar Saas seer nee 1 
Transverse diameter______ fora a eee : 
Depth of lower jaw below first true molar --------------- 
The only specimens of this species now known are 
lower Eocene of Wyoming. 
