EVOLUTION OF THE ELEPHANT — LULL. 673 



ridges seems to be a matter of degeneracy, which casts some doubt 

 upon the vahie of the subgenus Loxodonta. Elephas africanus de- 

 ployed over the whole of Africa with the exception of the Sahara 

 Desert. It also crossed to Gibraltar and spread over most of the 

 Spanish Peninsula. It has since been extirpated, however, in all 

 of the region north of the Sahara. The living Indian elephant 

 exhibits similarity of structure with the E. antiquus, a form known 

 as Elephas armeniacus, found in Asia Minor, being annectent type. 

 Elephas indicus may have come from Elephas insignis through the 

 Lower Pleistocene E. hysudricus, and probably represents a purely 

 local evolution, not a migratory form. 



A most perjDlexing question arises with reference to the origin of 

 the great North American elephants, Elephas imperator^ E. colurribi^ 

 and finally' E. pnTnigenius itself. Emphasis has been placed on the 

 similarity existing between the American and European elephants, 

 though I know of no expression of opinion as to the actual relation- 

 ship of the forms in question. In tooth characters Elephas eolumbi 

 is certainly suggestive of its European contemporary, E. antiquus^ 

 while E. imperator somewhat resembles E. meridionalis. The tusks, 

 which are so important from the developmental standpoint, have ap- 

 parently been ignored, for the American types have huge spiral tusks, 

 while those of Elephas antiquus are nearly straight, and in E. 7neri- 

 dionalis they show by no means the development of E. imperator. It 

 is the writer's opinion that the American forms may prove to be a 

 distinct evolution, having been derived from some such form as 

 Elephas planifrons^ found in India from the Pliocene of the Siwalik 

 Hills to the Pleistocene of Xarbada Valley. We have no record of the 

 migration of E. planifrons^ but its progenitors and contemporaries 

 ranged, in some cases, as far as China and Japan by way of Burma. 

 This being an accustomed route, E. planifrons or a successor might 

 well have ventured beyond China to the northeast through Siberia, 

 across the Bering Isthmus, and thence southward as far as Mexico, 

 giving rise to the American form Elephas imperator^ which is first 

 reiDorted from the Equus or Sheridan beds (Lower Pleistocene). The 

 known range of the latter is from Nebraska to southern Mexico along 

 the one hundredth meridian, although specimens in the Yale collection 

 were found as far east as Ohio and west to the California coast. We 

 have the authority of Lartet for the finding of a tooth of Elephas in 

 the Lower Pleistocene in Cayemie, French Guiana. From the de- 

 scription of the " thick ridge plates " this specimen is evidently that 

 of E. imperator^ probably a stray to the southward before the condi- 

 tions which later prohibited proboscidian migration into South 

 America arose. It is the only recorded instance of a true elephant 

 known to me south of the Mexican Plateau. The geographical range 



