EDMONTON FORMATION 375 



The invertebrates corroborate the testimony of the vertebrates. The 

 identifications were made by Dr. T. W. Stanton, whose comments are as 

 follows : 



"I have recently examined your invertebrates from the Edmonton and 

 Paskapoo formations of Alberta. Those which you have already sent from 

 the Edmonton beds include several lots composed of brackish-water shells, 

 with a slighter mixture of marine forms (Lunatia) and several lots of purely 

 fresh-water shells. The brackish-water collections are certainly Cretaceous, 

 and consist of species which all occur either in identical or very closely 

 related forms in both the Judith River and in the brackish-water bed, which 

 occurs at the top of the Fox Hills and the base of the Lance. 



"The fresh- water collections contain no species characteristic of either the 

 Judith River or the Lance, and while some of them, like Goniohasis tenuicari- 

 nata, occur in the Lance, the general aspect of the fossils is somewhat more 

 suggestive of the Fort Union species as occurring in the Belly River beds of 

 Alberta, and it may be that more of these types than we have supposed range 

 down as low as the Judith River." 



The plant remains from this formation, though not extensive, are 

 nevertheless of considerable importance. Practically all of the described 

 species were made known from later deposits, and few if any of the 

 species have been found in earlier deposits. The paleobotanists (Dr. 

 F. H. Knowlton and Dr. A. Hollick) who have examined this collection 

 are of one opinion that the plants are of Fort Union age. The Edmonton 

 beds are practically horizontal, and the stratum containing all but one of 

 the identified species of plants lies 250 feet below that in which plesio- 

 saurs (animals of accepted Mesozoic age) occur. 



It seems not impossible to reconcile the evidence of the flora with that 

 of the fauna. The location of the plants is positive and the determina- 

 tion admitted, but their significance has probably been misinterpreted. 



Lesquereaux, in the study of Cretaceous floras, long ago expressed the 

 opinion "that groups of identical fossils, especially vegetable ones, do not 

 prove or indicate contemporaneity of the formations which they charac- 

 terize when these formations are observed at great distances or under 

 different degrees of latitude.'' 



In this upper part of the Cretaceous called into question by the pres- 

 ence of Eocene plants it is probable that Eocene climatic conditions had 

 already begun. During the close of the Cretaceous and the beginning of 

 the Tertiary there was a long period of equable climate, and it is evident 

 that the flora was temperate and of wide-spread distribution. For these 

 very good reasons the plant remains do not prove whether widely sepa- 

 rated beds that contain the same species are strictly contemporaneous or 

 successive. 



