206 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



wood, and Evans, the type of which is the second 

 specimen described by Leidy, namely, Evans's speci- 

 men (Nat. Mus. 113). This specimen is believed by 



FiGUEE 161. — Type (holotype) of Palaeoiherium maximum 

 Parts of the outer wall (the ectoloph) ot two upper molars. After Leidy, 1862. Natural size. 



Osborn to be congeneric with the type of Menodus 

 giganteus Pomel. 



Proposal of the generic name TitanotJierium. — After 

 describing under the name Palaeotherium? 

 proutii the specimens made known by Prout 

 and by Owen, Norwood, and Evans, Leidy /' 



(1852.1, p. 552) says: 



All the preceding specimens, except probably the 

 latter two, I suspect belong to a different genus from 

 either Palaeotherium or Anchitherium, and should the 

 suspicion prove correct, Tilanotherium would be a 

 good name for the animal, as expressive of its very 

 great size. 



Palaeotherium maximum Leidy, 1852 



Original reference. — Leidy, in Owen, Report 

 of a geological survey of Wisconsin, Iowa, 

 and Minnesota, description of tab. 12 B, figs. 

 3, 4, 1852 (Leidy, 1852.1). 



Type locality and geologic horizon. — White 

 River, "Nebraska" [South Dakota]; Chadron 

 formation {Titanotherium zone). 



Type. — Parts of the outer wall or ectoloph 

 of two superior molars. Types now lost- 

 (See fig. 161.) 



Characters. — Leidy writes: "I am at pres- 

 ent very much inclined to consider these as 

 belonging to a true species of Palaeotherium, 

 which from its very great size might be 

 appropriately named Palaeotherium maxi- 

 mum." 



Etymology. — maximum, greatest — that is, 

 greater than P. magnum. 



Present determination.— These fragments belong to 

 a large Oligocene titanothere of wholly uncertain 

 reference. 



Rhinoceros americanus Leidy, 1852 



Original reference. — Acad. Nat. Sci. Philadelphia 

 Proc, vol. 6, p. 2, 1852 (Leidy, 1852.2). 



Subsequent reference. — Leidy, 

 The ancient fauna of Nebraska, 

 p. 76, pi. 17, figs. 1-4, 1853 CLeidy, 

 1854.1). 



Type locality. — White River, 

 "Nebraska" [South Dakota]. 



Type. — Two superior premolars 

 belonging upon opposite sides of 

 the jaw. Part of a collection pro- 

 cured by Mr. Thaddeus A. Cul- 

 bertson for the Smithsonian Insti- 

 tution. Types not located. (See 

 fig. 162.) 



Characters. — The proceedings 

 of the Philadelphia Academy con- 

 tain the following note: 



Dr. Leidy called the attention of the members to a fossil 

 tooth and a fragment of a second, from the collection made by 

 Mr. Culbertson in Nebraska Territory, which, he observed, 

 belonged to a new species of Rhinoceros, or probably Acero- 



FiGURE 162. — Cotypes of Rhinoceros americanus 

 Two upper fourth premolars. After Leidy, 1853. Natural size. 



therium. The former specimen is probably a third premolar, 

 the latter a portion of the fourth. A great peculiarity in the 

 teeth is the confluence of the inner lobes with each other and 

 their separation to the base from the outer lobes. They 



