Vol. 5] 



Merriam-Sin claii 



. — Tertiary Faunas. 



183 



A still later table is the following by Hatcher: 114 

 r Goodnight = Palo Duro = Ogalalla 



Miocene 



Loup Fork 1 Nebrasca = Upper Deep River 



] Harrison = Hiatus between Lower and Upper 

 Deep River. 



( Monroe Creek - Upper John Day and Lower 

 Arikaree < Deep River. 



{ Gering Sandstone = Lower John Day 



f Leptauehenia Clays, including Protoceras Sand- 



Oligoeene = White River 



J 



stones. 



Oreodon Clays, including Metamynodon Sand- 

 stones. 



Titanotherium Sandstones and Clays. 



The reasons which have governed the determinations of geo- 

 logic age and stratigraphic equivalency expressed in the table 

 on page 173 of the present paper are stated at length in the fol- 

 lowing chapters : 



THE JOHN DAY. 



Palaeontological Classification. — Two faunas may be recog- 

 nized in the John Day, corresponding to the middle and upper 

 stratigraphic subdivisions. The Lower John Day will probably 

 prove to be faunally distinct from the beds above, but until its 

 fauna is better known it must be left without a palaeontologic 

 designation. 



Wortmam 11 "' has proposed a subdivision of the series into lower 

 or Diceratherium beds and upper or Merycochoerus beds, the 

 former corresponding to the middle and the latter to the upper 

 of the three subdivisions now recognized. The value of the term 

 "Diceratherium beds" is greatly diminished by the difficulty 

 of identifying Diceratherium in the field, owing to the usual 

 fragmentary character of much of the rhinoceros material en- 

 countered. As yet it is also not altogether certain that the genus 

 is confined to the Middle John Day. 



The palaeontological designation of the Upper John Day 30 has 



:: <Proc. Am. Phil. Soc, Vol. 41, p. 118, 1902. 



' M Extinct Camelidae of North America. Bull. Am. Mus. Nat. Hist., 

 Vol. 10, p. 120. 



30 Merycochoerus beds. Wortman. Bull. Am. Mus., Vol. 10, p. 120. 

 Paracotylops beds. Merriam. Bull. Dept. Geol. Univ. Cal., Vol. 2, p. 296. 

 Promerycochoerus beds. Matthew. Memoirs Am. Mus., Vol. 1, pt.7, 

 legend of 'fig. 19, p. 399. 



