242 EXTINCT MONSTERS 
and part of a fifth. It had a wide range in America and Europe. 
The next stage is seen in the Hyracotherium (see Fig. 88), also 
known as Protorohippus. Its skull and forefoot are shown in 
Fig. 89. A nearly complete specimen was found by Dr. J. L. 
Wortman in the Big Horn Mountains of North Wyoming. It 
Fig. 88. — Skeleton of Hyracotherium venticolum, from Eocene strata, North America. (After Cope.) 
