CENozoic (interior). 291 
Feet. 
Nebraska (Hayden), 150 
Central Dakota (Cope), 200 
The Wliiteriver series corresponds to the Oligocene of some 
authors. Thus there occur in both Europe and America at this 
period the genera Elotherium, Hyaenodon, Cynodictis, Ischy- 
romys (= Sciuromys teste Schlosser in litt.), ? Pterodon (? Hemip- 
salodon teste Schlosser in litt.), and Agriochoerus ( ? Ha'plomeryx). 
Other European Oligocene genera occur in the Johnday series, 
as Meniscomys {^=^ Sciurodon teste Schlosser in litt.) and (? = Ael- 
urogale) Archeelurus (Schlosser in litt.). 
Johnday. — Mammalia. Presence of Nimravidse, Poebrothe- 
riidse, Tragulidse, Elotheriidse, Suidse, Muridse and Saccomyidse. 
Absence of Lemuroidea and Creodonta ; of Hystricidse, Felidse, 
Ursidfe, Camelidae, Equidee, and Proboscidia. 
This formation occupies a considerable tract on the upper part 
of the course of the John Day River in Oregon. King states 
that it extends north into Washington and south into Nevada, 
but, according to White, the beds from the latter State, to vs^hich 
King gave the name Truckee, are of later age. According to 
Marsh the Johnday beds have a thickness of four or five thou- 
sand feet. The vertebrate fauna is very rich. 
The beds in the valley of the North Fork of the John Day 
River present some faunal peculiarities, but their significance is 
unknown. 
TiCHOLEPTUS. — Mammalia. Presence of Anchitherium, Pro- 
boscidia, and Camelidse, and the Oreodont genera Merycochcerns, 
Merychyus, Cydopidius, and Pithecistes. Absence of ? Elothe- 
riidse, ? Poebrotheriidse, ? Nimravidse, and Cosoryx, 
This horizon requires further exploration, as but twenty species 
have been thus far determined from it. But it is evidently inter- 
mediate in age between the Johnday and Lou])fork epochs, 
with greater affinities to the latter. It differs from the latter 
in the presence of Anchitherium and numerous genera and 
species of Oreodontidae, and in the absence of Cosoryx. The 
formation is known from three regions : first, from Western Ne- 
braska ; second, from the valley of Deep River, Montana ; and 
thircl, from Cottonwood Creek, Oregon. Its thickness has not 
been yet stated. 
LouPFORK. — Mammalia. Presence of Felidse, Camelidse, 
