168 SYSTEMATIC PALEONTOLOGY 



broad and deep as to appear swollen; teeth with enamel folds about $ 

 of an inch apart, or 12 in 10 inches, the part of the jaw in advance of 

 the teeth being almost vertical, much as in E. primigenius, but on a vastly 

 larger scale. 



The tusks, which reach an enormous length, are of the typical Ele- 

 phas pattern, being comparatively slender and but slightly tapering. A 

 specimen in the American Museum of Natural History is 13 feet long 

 and 22 inches in circumference, and Professor Osborn notes a specimen 

 in the Museum of the City of Mexico having a length of 16 feet, this 

 being at the present date the longest tusk on record and one that will 

 probably never be much surpassed in dimensions. 



While this fine species has never been recorded save in the interior of 

 the continent where it extends from Nebraska to the valley of Mexico, 

 it is well to consider it here. Typical examples may be distinguished at 

 a glance by the coarseness of the enamel folds which are nearly an inch 

 from center to center, 31 folds being comprised in 26 inches. In size it 

 is one of the largest, if not the very largest, of elephants, comparing in 

 this respect as well as in structure of teeth with Elephas antiquus and 

 meridionalis of southern Europe, which it seems to have exceeded in 

 height. While Gaudry claims for E. antiquus a height of 13 feet 1 inch 

 (3.95 m.) yet he states that the femur of this species is 130 cm. long 

 and that of E. meridionalis 124 cm. Now the femur of the African 

 elephant " Jumbo " is 133 cm. long, or slightly greater than that of either 

 of these two fossil species, although Jumbo was but 11 feet high at the 

 shoulders. Granting that the hind legs of the extinct species were pro- 

 portionately shorter than in the living elephant, it would seem that the 

 height assigned to the elephant of Durfort is entirely too great. A femur 

 of E. imperator is reported from Keene, Oklahoma, as having a length 

 of 5 feet 1 inch, or 141 cm., and this corresponds with examples from Vic- 

 toria, Texas, in the American Museum of Natural History. Taking 

 this material as a basis, we may estimate the height of the Imperial mam- 

 moth to have been 13 to 13^ feet, so that this is almost the only species 

 that comes anywhere near realizing the popular idea of a mammoth. 



The re-establishment of Elephas imperator as a valid species was due 



