Measurements.
| M. | |
| Greatest length of astragalus | 0·021 |
| Greatest breadth of ditto | ·018 |
| Length of neck of ditto | ·005 |
| Width between the condyles | ·010 |
| Vertical diameter of face for navicular | ·012 |
| Transverse diameter of ditto | ·012 |
| Length of calcaneum | ·046 |
| Width of face for cuboid | ·006 |
From Henry's Fork.
OROHIPPUS, Marsh.
Am. Jour. Sc. vol iv., p. 207, third series.
Generic Characteristics.—"The crowns of the upper true molars are composed of a pair of external cusps similar to those of anchitherium. There are two corresponding inner tubercles, from which ridges extend obliquely to the anterior inner margin of the outer cusps; but the anterior ridge is divided so as to form an intermediate anterior tubercle. All the teeth preserved have a distinct basal ridge."
Species Known.—
| Orohippus pumilus, Marsh. Orohippus major, Marsh. Orohippus agilis, Marsh. Orohippus gracilis, Marsh. |
Orohippus pumilus? Marsh.
Specimen obtained. Penultimate and third superior molars, with part of zygoma.