390 ZOOLOGY. 



ures, the Permian, the Laramie, the Maestrichtian, the Eocene, and the 

 Miocene, but (3) several of the restricted divisions seem to be exactly 

 parallel, as the Turonian with the Niobrara, the Suessonian with the 

 Wasatch, and the JEquus beds with the Pliocene. 



In conclusion, a comiiarison is instituted between the results derived 

 from the examination of the vertebrate remains and those obtained from 

 a study of the fossil plants: (1) The beds determined by Cope from the 

 vertebrate remains to be Upper Cretaceous were identified by Lesquereux 

 from the plants as Lower Eocene ; (2) the Lower Eocene of Cope is 

 called by Lesquereux Miocene ; and (3) the Middle Eocene of Cope 

 answers to the Upper Miocene of Lesquereux. The discrepant results 

 thus obtained are remarkable and, says Professor Cope, there are only 

 two possible explanations : " Either the animal life of North America has 

 lagged behind that of Europe by one period during past geologic time, 

 or, secondly, the vegetable life of America has been equally in advance 

 of Europe during the same period. In other words, if the plant-life of 

 the two continents was contemporaneous, ancient types of animals 

 remained a period longer in North America than in Europe. If animal 

 life was contemporaneous, plant-life had advanced by one period in 

 Europe beyond that which it had attained in North America." 



The necessity for further critical comparisons and study from a large 

 point of view thus becomes obvious, but it must be added that the 

 deductions formulated by Professor Lesquereux are antagonized not 

 only by the vertebrate, but also by the invertebrate remains of the same 

 strata. 



