1899] MICROSCOPICAL JOURNAL. 49 



Diatoms Prove an Occidental Sea on the East of 

 tiie Rocivy Mountains. 



By ARTHUR M. EDWARDS, M. D., F. L. S. 



The Occidental Sea I have endeavored to describe, at 

 fir8t in the American Journal of Science for 1891 and 

 elsewhere in various publications, and why I describe it 

 as Eocene, below the Miocene of California, I have also 

 stated. But the sea was only stated to be west of the 

 Rocky Mountains, between that range and the Sierra Ne- 

 vada. Some specimens I had from the east of the Rocky 

 Mountains seemed to be Eocene but I was not sure that 

 they were more ancient than the Iceberg period or Cham- 

 plain. In fact, I did not get any specimens that were 

 surely Eocene. Now, I have one that comes from the 

 "Public Lands" on the branches of the North Canadian 

 or Beaver Creek about thirty-five or forty miles from En- 

 glewood in the northeastern part of Kansas. This, Prof. 

 F. W. Cragin of the Colorado College calls the Loup 

 Fork terraine, and I have to thank him for an opportu- 

 nity of examining it. It is also east of the Rocky 

 Mountains and therefoFe extends, as I expected, the Oc- 

 f cidental Sea to the eastward. I hope ere long to extend 

 it on the coast side of the Sierra Nevada and into Cali- 

 fornia. In fact, I have it from Shasta and Anacapa Is- 

 land on the coast, showing that it covered a vast extent 

 of country and was a large body of water. When a 

 sample was shown to Prof. Cragiu, in 1888, the chalky 

 marl was thought to be of Cretaceous age and also car- 

 bonate of lime, in fact the same as chalk. But, he visited 

 the locality in 1890 and found that it was impossible, as 

 fossils in the same bed were l^nd and lake animals. In 

 1896, he visited the locality again and confirmed the con- 

 clusion that the Loup Fork was lacustrine. He says that 

 "the great Loup Fork Lake which extended from middle 

 Kansas to the Rocky Mountains and from Texas to British 



