The discovery of the fossil skeleton of an animal previously known only from fragments or from the skull is always an event of interest, as it confirms or negates preliminary impressions. Of the three skeletons here described, two serve to establish the genera to which they were first assigned; but the third differs widely from what the skull had led one to expect, pointing to the conclusion that the genus Promerychoehoerus, to which it was first assigned, is composed of highly divergent forms.
In 1931 a field party from Amherst College found a deposit on Porcupine Creek, South Dakota, in which fossil leg bones with complete feet were the outstanding feature, although there were also some skulls, vertebræ, and other bones. The animals represented, all of which were relatively small, included Oligobunis, Nanotragulus, and Merychyus curtus. This last species was established by Loomis2 in 1924 from . . .