Transactions of the American Philosophical Society .. . ppermost beds, but loose fragments were found in the middle of the upper stratigraphically, these specimens are of no especial interest. 180 THE MAMMALIA OE THE DEEP RIVER BEDS. Summary. It will be convenient to sum up briefly here the principal results of this investi-gation. (1) The beds of the Deep River valley belong to two horizons, as originallypointed out by Grinnell and Dana. These horizons differ widely in lithologicalcharacter and even more markedly in their contained fossils, and are almost certainlyseparated by a
Transactions of the American Philosophical Society .. . ppermost beds, but loose fragments were found in the middle of the upper stratigraphically, these specimens are of no especial interest. 180 THE MAMMALIA OE THE DEEP RIVER BEDS. Summary. It will be convenient to sum up briefly here the principal results of this investi-gation. (1) The beds of the Deep River valley belong to two horizons, as originallypointed out by Grinnell and Dana. These horizons differ widely in lithologicalcharacter and even more markedly in their contained fossils, and are almost certainlyseparated by an unconformity of erosion, which represents a considerable lapse oftime. The lower series should be placed at the summit of the John Day and theupper at the base of the Loup Fork, where they form a well-marked subdivision (theTicholeptus beds of Cope). This subdivision is not certainly known in other regionsthan the present one, and the deposits in Oregon, Nebraska and Wyoming whichhave been referred to it most probably belong to the Loup Fork MAP OF UPPER SMITH BIVER VALLEY, by W. B. Harris from a sketch by 0. C. Mortson. (2) The nearest European equivalent of the upper Deep Eiver beds appears tobe the upper Miocene of Sansan and Simorre. (3) In the genus Gynodesmus, which has the dentition of Canis combined withthe skull and brain of the more ancient genera of the phylum, we find an importantlink in the genealogy of the dogs, leading back to the White River form, Daphczmis,through some as yet unknown genus of the lower John Day, which, however, musthave been not unlike the so-called Temnocyon josejjhi. The abundance of Miocene THE MAMMALIA OF THE DEEP RIVER BEDS. 181 dogs in North America, contrasted with their absence or unimportance in Europe,renders it very probable that the family originated in the former continent. (4) The name Anchitherium has been improperly applied to American equinesfrom the White River and John Day, and should be replaced by M
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