Ch. XV.] LOWER MIOCENE— NEBRASKA. 279 



cal distribution of mollusca date back to a period as remote as that 

 of tlie Miocene strata. 



Of ten species of zoophytes which I procured on the banks of the 

 James River, one was formerly supposed by Mr. Lonsdale to be iden- 

 tical with a fossil from the faluns of Touraine, but this species (see 

 fig. 209) proves on reexamination to be 

 different, and to agree generically with a ri s- 209 - 



coral now living on the coast of the Uni- 

 ted States. "With respect to climate, Mr. 

 Lonsdale regards these corals as indicating 

 a temperature exceeding that of the Medi- 

 terranean, and the shells would lead to "12 

 similar conclusions. Those occurring on 

 the James River are in the 37th degree of 

 X. latitude, while the French faluns are in 

 the 47th ; yet the forms of the American *st™Qf f 7 f to < Lonsdale. 



' J m Syn. Antnophyllum Uneatwm. 



fossils would scarcely imply SO warm a cli- Williamsburg, Virginia. 



mate as must have prevailed in France 

 when the Miocene strata of Touraine originated. 



Among the remains of fish in these Post-eocene strata of the Uni- 

 ted States are several large teeth of the shark family, not distinguish- 

 able specifically from fossils of the faluns of Touraine. 



LOWER MIOCENE, UNITED STATES. 



Nebraska. — In the territory of Nebraska, on the Upper Missouri, 

 near the Platte River, lat. 42° K, a tertiary formation occurs, con- 

 sisting of white limestone, marls, and siliceous clay, described by Dr. 

 D. Dale Owen,* in which many bones of extinct quadrupeds, and of 

 chelonians of land or freshwater forms, are met with. Among these, 

 Dr. Leidy describes a gigantic quadruped, called by him Titanothe- 

 rium, nearly allied to the Paloeotherium, but larger than any of the 

 species found in the Paris gypsum. With these are several species 

 of the genus Oreodon, Leidy, uniting the characters of pachyderms 

 and ruminants also ; Eucrotaphus, another new genus of the same 

 mixed character ; two species of rhinoceros of the sub-genus Acero- 

 therium, sl Lower Miocene form of Europe before mentioned ; two 

 species of Archwotherium, sl pachyderm allied to Charopotamus and 

 Hyracotherium ; also Poebr other ium, an extinct ruminant allied to 

 Dorcatherhim, Kaup ; also Agriochcegus of Leidy, a ruminant allied 

 to Merycopotamus of Falconer and Cautley ; and, lastly, a large car- 

 nivorous animal of the genus Machairodus, the most ancient example 

 of which in Europe occurs in the Lower Miocene strata of Auvergne, 

 but of which some species' are found in Pliocene deposits. The tur- 



* David Dale Owen, Geol. Survey of Wisconsin, &c. ; Philad. 1852. 



