382 GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. 



the Upper Miocene it becomes more complex, but is still small and 

 erect, like that of the roe. In the Pliocene it becomes larger and 

 longer, and altogether more complex and differentiated, some forms, 

 such as the Cervus dicranios of Nesti, being the most complicated 

 antlers known either in the living or fossil state. These succes- 

 sive changes are analogous to those which are to be observed in 

 the development of the antlers in the living deer, which begin 

 with a simple point and increase their number of tines until their 

 limit is reached. It is obvious, from the progressive diminution 

 in size and complexity of the antlers in tracing them back from 

 the Pliocenes into the Upper and Middle Miocenes of Europe, that 

 in the latter period we are approaching the zero of antler devel- 

 opment. In the Low r er Miocenes I have failed to meet with evi- 

 dence that the deer possessed any antlers." 13 



The roe, stag, elk, and reindeer occur fossil in the Quaternary 

 deposits, together with a giant form, the Irish stag (Cervus me- 

 gaceros), whose extinction appears to have been effected long after 

 the region inhabited by it was also inhabited by man. The stag 

 (wapiti), elk, and reindeer also occur fossil in the American Post- 

 Pliocene deposits, the last, as in Europe, in latitudes very much 

 lower than it now occupies. The genus Cervus dates from the 

 Pliocene. A Quaternary form intermediate in many points of 

 structure between the true deer and the elk, and originally re- 

 ferred to the latter, has recently been re-described by Scott as Cer- 

 valces (C. Americanus). Its remains have thus far been met with 

 only in New Jersey and Kentucky. The hornless Miocene genus 

 Leptomeryx, which by Leidy and Marsh is placed near the Cervidae, 

 is by Kutimeyer considered to more nearly approach the camels. 



Of undeterminable position among the Ruminantia, but more or 

 less closely related to each other, and showing certain analogies of 

 structure with the Tragulina, are the Old World Lower and Middle 

 Tertiary genera, Anoplotherium, Xiphodon, Dichobune, and Caino- 

 therium. An equally aberrant type of American ruminants, the 

 " ruminating hogs " (Oreodontidae) of Dr. Leidy, whose remains are 

 exceedingly abundant in the Western Territories, appears to have 

 been nearly related to the Anoplotheridae. Thirty-five species, 

 with three exceptions (Merychyus Pliocene), all belonging to the 

 Miocene period, are referred to this family by Professor Cope. 131 



