2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6o 



eland, T. oryx, differing from them only in minor details which, 

 except for their somewhat larger size, mark them as slightly less 

 progressive than those of the African species. These differences, 

 however, do not seem sufficient to he regarded as of generic impor- 

 tance. Since, therefore, judged from the material in hand, there is 

 no obvious reason for separating the American fossil species from 

 the living genus Taurotragus, except perhaps the insufficient one of 

 the seeming absurdity and improbability of the case, I have here 

 referred it to that genus, although more complete material may later 

 show this reference to be unwarranted. Whether properly belong- 

 ing to the African genus or not, it is undoubtedly not only strepcis- 

 serine in its affinities, but seems especially closely allied to the living 

 species of this- group. Its occurrence, therefore, in the Pleistocene 

 of the eastern United States is most unexpected, and seems to have a 

 special significance in reference to the probable migrations and world 

 distribution of these large antelopes during the Pleistocene period. 

 It suggests that the strepcisserine group of the antelopes were com- 

 paratively recent migrants to thai portion of Africa south of the 

 Great Sahara Desert, where alone they now survive, the common 

 center of dispersion in Pleistocene times being somewhere in central 

 or southern Asia, as it certainly seems to have been at the beginning 

 of the Pliocene, when several now extinct species of the group 

 inhabited India and others invaded northern Africa and Europe. 

 Much later, apparently, still other members of the group crossed 

 directly into lower Africa, probably by way of some then existing 

 land connection south of the Red Sea. while one species at least 

 migrating northeastward from this same Asiatic center, evidently 

 found their way across the Pleistocene Alaskan land bridge into 

 America and thence southeastward to the eastern United States. 

 The fact that no remains of this animal have been found in any of 

 the Pleistocene deposits of the west, which deposits are better 

 exposed and have been so much more thoroughly explored than 

 those of the east, suggests that the time of this migration to America 

 was possible during one of the interglacial epochs, when there was a 

 route open to the north of the Great Lakes by which they may 

 have reached the eastern coast region without traversing the plains 

 country. It is possible that the moose, carabou, cervalces, and per- 

 haps some of the other Pleistocene and present-day mammals com- 

 mon to the eastern coast region, may also have found their way 

 from the Old World by some such direct route. However, far more 

 data than are now available would be necessary to establish the truth 

 of such an hypothesis. 



