998 The Perissodactyla. 
from that of a sheep to that of a kit-fox. Several species of — 
Helaletes have been described from the Bridger Eocene.’ The 
species of Hyrachyus are rather numerous, and range through 
11. Lophiodon isselensis, superior molars three-fifths natural ee py 
Fic. 
Middle Eocene of France. From Gaudry, “ Enchainements du Régne 4m 
the Wind River, Bridger, and Diplacodon beds. Dilophodon 
has two species and Colonoceras one species, in the Bridget. 
Lophiodon is, so far as yet known, confined to Europe - 
of its species, Z. rhinoceroides, was as large as a medium-sized 
rhinoceros, and several species ranged in dimensions to those 
of asheep. They appear in the Bruxellian, and range aprem 
through the Bartonian.. Heptodon is, so far, only American, l 
two species, a large and a small, are found in the Wasii i 
formation, and two, of intermediate size, in the Wind River. . 
France, 
and [seto 
FIG, 12. Protapirus priscus Filh., Phosporites of Quercy, 
natural size. From Filhol. 
Protapirus is from the Phosphorites of France; 
