APPENDIX. 



Art. XXXVI. — Description of Tertiary Artiodactyles / 

 by O. C. Marsh. 



The main object of the present paper is to figure, and to 

 describe more fully, several interesting ungulate mammals, 

 which have been previously named and noticed by the writer. 

 A number of others, mostly allied forms, are here described for 

 the first time. The specimens discussed are chiefly from the 

 western part of the country. Some of them from the Miocene, 

 however, are apparently identical with those found on the 

 Atlantic coast, and thus for the first time it is possible to make 

 out a definite horizon in the Tertiary, extending nearly across 

 the continent. 



Eocene Bunodont Artiodactyles. 



The Artiodactyles known from the Eocene of this country 

 are few in number, and nearly all small generalized forms. 

 The oldest hitherto found appear to have suilline affinities, but 

 the others cannot be placed with any certainty in any of the 

 existing groups. The first Artiodactyles, so far as now known, 

 are preserved in the lower Eocene, in the horizon named by 

 the writer the "Coryphodon beds," and these are all primitive 

 forms. In the middle Eocene, especially in the " Dinoceras 

 beds, " the remains of these mammals are more abundant, and 

 some of them permit accurate determination. In the upper 

 Eocene, in the Diplacodon horizon, more specialized forms 

 occur, and for the first time resemblance to several modern 

 types can be recognized. 



Eohyns distans, sp. nov. 



The present genus was proposed by the writer in 1877, in 

 an address before the American Association for the Advance- 

 ment of Science.* In reviewing the extinct ungulates of this 

 country, the following statement was then made in regard to 

 the present group : — 



* Introduction and Succession of Vertebrate Life in America, this Journal, vol. 

 xiv, p. 362, 1877. 



Am. Jour. Sci— Third Series, Vol. XLVIII, No. 284.— Sept., 1894. 

 17 



