Douglass : Dromomeryx. 461 



the molars of Blastomeryx borealis differ from Cosoryx \Merycodus\ 

 as much as those of the deer differ from those of the antelope ; those 

 of ^^Blastomeryx''' and the deer being brachyodont, while those of 

 Cosoryx, and the " anteloi)e " {A/ifi/ocapra) are hypsodont. 



In his "Mammalia of the Deep River Beds" Scott gave some 

 characters of Blastomeryx borealis Cope. He says " The skull is re- 

 markable for the high and narrow occiput the upper portion of which 

 is drawn out into a long backwardly projecting process composed of 

 the parietals and supraoccipitals, which is very similar to the corre- 

 sponding part of the occiput of the Oreodontidae. The horns are 

 trihedral at the base gradually becoming rounded distally and are of 

 remarkable length ; they are perfectly simple and unbranched, and in 

 no specimen which I have seen is there any trace of a burr. The 

 surface of the horns is faintly marked by vascular impressions, but is 

 on the whole remarkably smooth, much more so than in the antlers oi 

 the deer, and, as Cope has suggested, they were doubtless covered 

 with skin during the lifetime of the animal. . . . The upper premolars, 

 three in number, have the internal crescent, deuterocone, complete ; 

 P^ and P^are massive and oval in section, while PA is more extended 

 transversely. The molars are very brachyodont and are covered with 

 very rugose and strongly wrinkled enamel ; the internal crescents are 

 complicated by accessory spurs which invade the valleys. The internal 

 pillar or style is very variable, being sometimes quite large, while in 

 many specimens it is absent from one or the other of the molars. ' ' 



Dromomeryx gen. nov. 

 I propose the name Dromomeryx (running ruminant) for this genus 

 of American fossil mammals including Blastomeryx borealis Cope, B. 

 atitilopini/s Scott, and perhaps Palceomeryx americaniis Douglass, and 

 P. madisonius Douglass. Blastomeryx borealis Cope was the first to 

 be described, so this would become the type-species of the genus. In 

 the collections of the American Museum of Natural History the less 

 complete skull (Fig. i) but the one which possesses the greater por 

 tion of a horn (No. 8132) is marked on the label as the "type" 

 and the more nearly complete skull (No. 8133) is indicated as the 

 " co-type." Cope's original labels do not accompany the specimens, 

 so I do not know whether or not Cope selected one specimen as 

 the type, but he apparently used both skulls in his original diagnosis 

 of the genus and species. There appear to be no important differ- 



