15 



it at the same time as synchronous with those of the Green Eiver epoch. 

 The writer has attained the same opinion on paleontological grounds, 

 and has hence employed the same name for both areas, namely, the 

 Green River epoch.* 



As already stated,t the upper or red-banded Tertiary beds of this local- 

 ity yielded the following species: 



Ferissodaetyle bones, two species. 

 Orotherium vasacciense. 

 Crocodilus, sp. 

 Alligator heterodon. 

 Trionyx scutumantiquum. 

 Emys testudineus. 



gravis. 

 Clastes glaber. 

 Unio, two species. 



The lower sandstone beds yielded the following mammals: 



Bathmodon radians. 



semicinctus. 



latipes. 

 Orotherium index.* 



* Cope, Paleontological Bulletin, No. 17, 1873. 

 Fhenaoodus primcemis. 



West of the contact of Bear Eiver with the Tertiary bluflfs the strata 

 consist of sandstone and conglomerates, and dip at about 30^ to the 

 northeast. Five hundred feet vertically below the Bathmodon bed a 

 stratum of impure limestone crops out, forming the slope and apex of a 

 portion of the bluflf. In this I found the following vertebrates : 



Eeptiles : Trionyx scutumantiquum. Fishes : BMneastes calvus. 

 Emys (f) euthtunes. Clastes glaber. 



In comparing this list with that given for the lower beds of the Green 

 Eiver epoch, where they overlie the Bitter Creek coal, such resemblance 

 may be observed as is sufiBcient to identify the two series. 



This is the nearest to a determination of the age of the Bvanstoh coal- 

 bed, which Hayden regards as the most important west of the Missouri 

 Eiver, that I have been able to reach. From the limestone just described 

 to the coal-bed, two miles to the west, the strata are very similar in 

 character and apparently conformable, so that they appear to belong to 

 the same series. Dr. Hayden confesses his inability to correlate them 

 with those of Bear Eiver City and Weber Eiver, but discovered remains 

 of plants which were identified with some of those known to occur in 

 the Fort Union beds, on the Laramie Plains, and the Upper Missouri. 

 If this be the case to a sufficient extent, the Evanston coal must be re- 

 ferred to that division of the Cretaceous period. This conclusion is, 

 however, only provisional, and Dr. Bannister's remarks* are much to 

 the point. He says : 



" In the upper beds northeast of Evanston," (the ones I describe above,) 

 " there seems to have been a considerable disturbance besides the mere 

 tilting of the beds, and from the altered direction of the strike* we were 



* Proceedings Acad, of Nat. Sciences, 1872, p. 279. 



t Proceedings American Philosophical Society, 1872, p. 473. 



* Hayden's Annual Report, 1872, p. 541. 



