ARTIODACTYLA 



165 



Wyoming, the National, the Carnegie, the Field museums, as well as 

 other institutions. Even private parties have been interested. 



This material collectively has furnished data which are far-reaching, 

 not only in paleontology, but in geology as well. Time and place do not 

 here permit of geologic discussion. However, in passing it is well to 

 mention that we have in the last few years happily emerged from the idea 

 of the supposed vast Tertiary inland lake, covering many States east of 

 the Eocky Mountains, to a much more reasonable supposition of actual 

 dry land, with smaller lakes, rivers, and forests which covered this same 

 Mississippi-Missourian area during the later Tertiary time. The com- 

 paratively recent activities of such men as Davis, Fraas, Gilbert, Hatcher, 

 Haworth, Matthew, Merriam, Williston, and others originally brought 

 about this change from field obsers'ations and from the study of the 

 faunae obtained. The proposed phylogenies of the Artiodactyla from 

 recent material collected have taken a considerable forward step, so that 

 if equal activities continue in the future it would appear that our text 

 books on geology and paleontology will have to be revised more often 

 than heretofore. 



Through systematic work in western Nebraska and eastern Wyoming 

 by the Carnegie Museum in 1900-1902 a certain series of sediments were 

 brought to considerable prominence (Hatcher, 1902), and in succeeding 

 years a number of other institutions were engaged in the same general 

 field. The Lower Miocene had long been wanting in the Tertiary strata 

 of our country, and the fauna of these beds is regarded as of very late 

 Oligocene or Lower Miocene Age. The Monroe Creek and lower Harrison 

 beds are especially looked on as Lower Miocene, while the upper Harrison 

 beds may be regarded as the base of the Middle Miocene. A rich verte- 

 brate fauna has been recovered from these sediments, which have assisted 

 much in recent phylogenetic studies. 



Dr. W. D. Matthew (1908) and Mr. Earl Douglass (1909) in some of 

 their work devoted to the Artiodactyla have finally relieved us of the 

 perplexity of grouping certain American Miocene genera (Merycodus, 

 Blastomeryx, and Dromomeryx) with contemporaneous European genera 

 {Paleomeryx, Dicrocerus, Amphitragulus, Dromotherium) . 



The small deerlike form Merycodus from the American Pliocene and 

 Capromeryx (Matthew, 1902, page 318) from the Pleistocene are placed 

 in a new family (Merycodontida'. Matthew, 1904) with equal raiik as the 

 Antilocapridae, the Cervidae, the Bovid?e, etcetera, while the new genus 

 Dromomeryx (Palceomeryx) Douglass is placed in the cervids under the 

 subfamily Pala^omervcinae. j\Tatthew would separate the European cer- 

 vids from those of the New World and has worked out a phyletic series 



