EDMONTON FORMATION 



373 



Glyptostrohus europoeiis (Brongn.) Heer Quercus ellisiana Lesq. 



Jiiglaus sp. 



Juglaus acuminata A. Br. 

 Juglaus laurifoUa Knowlton 

 Juglaus leconteana Lesq. 

 Juglaus occidentalis Newb. 

 Lastrea fischeri Heer 

 Maiauthcrium grandifolium Penh. 

 Nelumhium saskatchnense Dawson 

 Osmunda macrophylla Penh. 

 PhylUtes carneosus Newb. 

 Populus acerifolia Newb. 

 Populus arctica Heer 

 Populus cuneata Newb. 

 Populus dapUnogenoides Ward 

 Populus oMrita Dawson 

 Populus richardsoni Heer 



Quercus sp. 



Quercus ellisiana Lesq. 



Salix laramiana Dawson 



Sapindus sp. 



Sequoia conttsiw Heer 



Sequoia langsdorfii (Brongn.) Heer 



Sequoia nordenskioldii Heer 



SpJienopteris Moemstrandi Heer 



Sphenopteris guyotti Lesq. 



Sphenoxamites oManceolatus Penh. 



Taaoodium distichum miocenum Heer 



Taxodium occidentale Newb. 



Typha sp. 



Viburnum ovatum n. sp. 



Viburnum asperum Newb. 



Viburnum saskatchnense Dawson. 



EDMONTON FORMATION 



The terms Upper and Lower Edmonton should not be employed, for 

 the formation is lithologically and faunistically an indivisible unit. The 

 terms were originally used by the present writer as a check on the loca- 

 tion of fossils. When the entire series of beds were closely examined it 

 was found that such distinction was not warranted. 



The Edmonton formation consists chiefly of siliceous clays interstrati- 

 fied with seams of lignite and thin strata of whitish sandstones. It is 

 essentially a lignite formation. 



The strata are of marine and brackish-water origin and everywhere 

 conformably overlie the marine beds below. The whole series shows an 

 uninterrupted successive sedimentation from purely marine conditions 

 at the base through brackish-water during most of the' period, with a 

 gradual freshening toward the top. 



This formation fulfills the original definition of the term Laramie. 



Vertebrate remains are abundant. Neither mammalian nor fish re- 

 mains have been recorded. 



One turtle has been found at the base of the beds, and a turtle asso- 

 ciated with a rhynchocephalian and a crocodile were found near the top 

 of the formation. These* are semi-aquatic forms, and their remains 

 would be expected in sediments deposited chiefly in water, but they are 

 noticeably absent. It is evident that the environment was not suitable 

 to such forms. Marine vertebrates (plesiosaurs) are found as high as 

 the middle of the beds. 



