276 Tertiary. 



scalarinus, Pleurotoma moniliata, Pyrula multangulata, Solarium 

 cupola, S. delphinnloides, and Dentalmm microstria. 



In 1881, Prof. E. D. Cope* described, from beds supposed to belong 

 to the Puerco Group, Periptychus carinidens, and Deltatherium 

 fundaminis. From the Wind river Eocene, f Calamodon'oylindrifer, 

 Esthonyx acutidens, Sciurus hallovianus, Pantolestes secans, Mi- 

 crosyops scottianus. Miacis canavus, M. brevirostris, Didymictis 

 daiokinsianus, Ictops didelphoides, Bathyopsis Jissidens, Lamhdo- 

 therium hrownianum, Hyracotherium venticolum, and Phenacodus 

 trilohatus ; from the Miocene of the John Day river in Oregon, 

 Nimravus gompliodiis, N. confertus, Coloreodon ryderanus, PalcBO- 

 chmrus platyops, Protolahis prehensilis, and Pumys lockmgtonianus ; 

 and from the Am3'zon shales in the South Park of Colorada, of Upper 

 Eocene or Lower Miocene age, Charadrius shejjpardanus. 



We have passed, in historical review, the Tertiary as it has been 

 discovered, and is now known on the eastern, southern, and western 

 parts of the continent of North America, leaving for further considera- 

 tion, only the drift or fresh-water Pliocene and Post-pliocene of the 

 central part. The reason for separating the rocks in this manner 

 may be found in the fact that there is no connection between 

 the marine drift of the New England States and northeastern 

 shore of the continent, and the fresh-water drift or lake drift of the 

 central part, and as to the western part or Rocky mountain region, it 

 has never been subjected to any general drift action, though here and 

 there the waters from the local lakes have left their drift in and about 

 the streams that drained them. 



It may be important here to remark, that in this historical review, 

 geologically speaking, we have not found an}^ Glacial Period or Glacial 

 Epoch, nor palaeontologically speaking, have we found any evidence 

 whatever of such a period, nor have we found any phenomenon requiring 

 the intervention of such a period to explain it; but, on the contrary, 

 all the phenomena are to be accounted for, without change of climate, and 

 without the violation of anj^ of the laws of nature, which are now in 

 operation, and form the basis, from which the geologist judges of the 

 past. And when we come to a review of the drift of the central part 

 of the continent, it will appear equally as clear that no part of it was 

 the result of glaciers, and that so far as North America is concerned, 

 the so called Glacial Period never had an existence. 



* Am. Nat., vol. xv. 



t Bull. U. S. Geo. Sur.. vol. vi. 



