301 



River epoch to that which witnessed the deposition of the Lance Creek and 

 Hell Creek beds. Nevertheless, nothing can impair the force of the evi- 

 dence that many species included among the fishes, the tailed amphibians, 

 the turtles, the crocodiles, the champsosaurians, and the carnivorous and 

 herbivorous dinosaurs are represented in both formations by closely re- 

 lated forms. The remarkable thing about the matter is that the faunas of 

 the two formations, separated by so great a thickness of strata, should be 

 so similar. We must conclude that deposition went on rapidly in that in- 

 terval, so that it may not have been so long as otherwise might appear. 

 There could hardly have been movements of the land in that region that 

 produced any considerable changes of climate. During the Bearpaw epoch 

 the sea probably quietly invaded a part of the territory that had previously 

 been occupied by the Judith River animals ; but around the border of this 

 invading sea the turtles, the crocodiles, and the many genera of the dino- 

 saurs continued their existence and their evolution undisturbed until that 

 sea retired. And doubtless had all those animals in that region been 

 destroyed there was an extensive territory, nearly the whole of North 

 America as far as the Atlantic, that harbored similar forms, from which 

 territory new recruits could swarm in. As far away as New Jersey there 

 were living herbivorous and carnivorous dinosaurs not greatly different 

 from those of the Judith River beds. This appears to be true, that what- 

 ever happened to the plants between the time of the Judith River and the 

 Lance Creek beds, nothing of serious importance happened to the animals. 

 By those who insist on elevating the deposits of the Lance Creek 

 epoch into the Tertiary, a persistent effort has been made to minimize or 

 nullify the significance of the presence of dinosaurs. As long ago as 1S80 

 Heer wrote thus (Arctic Flora, vol. 6, pt. 2, p. 7) : 



Der Agathaumas von Black Buttes beweist daher keineswegs, dass 

 dort eine Tertiar-Flora zu gleicher Zeit mit einer Kreide-Fauna gelebt 

 habe, wie Prof. Cope dies behauptet, denn ein einzelnes Thi&r macht so 

 wenig eine Fauna aus, als eine Pflanzenart eine Flora. Wir konnen daher 

 Hrn. King nicht beistimmen, wenn er. mit Cope und Marsh, die Laramie- 

 Gruppe zur Kreide bringt. 



Mr. Cross and Dr. Knowlton have argued that the dinosaurs might 

 have continued on into the Eocene, and in fact did so. As to the verte- 

 brate paleontologists, it is not probable that any of them would have as- 

 serted that this was impossible and some of them have granted the possi- 

 bility. In holding that the dinosaur beds belong to the Mesozoic, they 



