List of Casts, Models, and Photographs. 4 1 



6. Elotherium, Giant Upper Oligocene Suilline. 



These animals have been depicted from very complete re- 

 mains in the American and Princeton Museums, and represent 

 the largest type of Oligocene Elothere, namely, the E. ramosiim 

 of Cope, or E. imperator of Marsh. The great flanges below 

 the cheeks for the attachment of the masseter muscles pre- 

 sented peculiar difficulties, and it is possible that they are 

 not here exhibited with sufficient expansion. The head is of 

 enormous size, but the chest is small, and the limbs are com- 

 paratively tall and stilted, as here represented. The very 

 remote relationship to the Pig and to the Hippopotamus is 

 suggested in the bristles and in the form of the lips. Elo- 

 therium is in a general way a sort of dry-land hippopotamus, 

 as Metomynodon is an aquatic rhinoceros ; in the one case the 

 dry-land type, in the other, the aquatic type, has become 

 extinct. 



Originally reproduced by Osbom in the Century Magazine, September. 1896. 

 Marsh, Am. Jour. Sci., XLVII, 1894, p. 408, pi. ix. 



7. Megacerops, Long-homed Lower Oligocene Titanothere. 



This group of male, female, and young is based upon skulls 

 belonging to different sexes and ages, in the American Museum 

 Collection, as well as upon the complete skeleton, No. 518, 

 mounted in the American Museum. There is no doubt that 

 the females had smaller skulls, with imperfectly developed 

 horns and narrow zygomatic arches, while the males of the 

 same species had extremely long, recurved horns. The ex- 

 tension of the premaxilla and the overhanging of the nares 

 by the rudimentary nasals indicate that there was not space 

 for a proboscis, but rather a prehensile upper lip, which sug- 

 gests the same structure in the Rhinoceroses. 



Originally reproduced by Osbom in the Century Magazine. September. 1896. 



OsBORN & WoRTMAN, Perissodactyls of the Lower Miocene White 

 River Beds, Bull. Am. Mus. Nat. Hist., VII, 1S95, pp. 346-352. 

 pU. viii, ix. 



