1895] MICROSCOPICAL JOURNAL. 345 



among the specimens Mr. Bell sent a fresh water mussel, 

 a Unio, "such," as he says, "as are common in Carson 

 river to-day." 



The following section of strata is given : 



Sandy clay 18 inches 



Sandstone 4" feet 



Clay 2 i"ch 



Sandstone IG feet 



Fine clay 2 feet 2 inches 



Coarse standstone 10 inches 



Sandy clay with tracks 3 inches 



Sandstone 18 to 24 inches 



Clay layer, with tracks 1 to 2 inches 



Sandstone below the quarry floor 38 feet 



So that the tracks seem to be in two layers, sandy clay 

 and clay. The tracks are as follows : Elephas or the 

 mammoth, elk or American reindeer, bos or buffalo, 

 horse, wolf, tiger, peccary, mylodon or giant sloth, birds 

 and the so-called "Homo Nevadensis" which it will be 

 seen is contemporaneous with the others, the mammoth 

 included. Prof. Marsh thinks these so-called Homo 

 Nevadensis are not human but formed by edentates, and 

 it appears reasonable. At any rate they are important and 

 mark the time when man did or did not exist in the 

 Eocene of the Occidental Sea. 



Now as to why I make the Carson City deposit Eocene. 

 You must include the Five Mile Canon, Virginia City, in 

 it, because I believe that is the lighter portion washed 

 from the Carson City deposit. I believe that they both, 

 the Carson City and Five Mile Canon, existed at the same 

 time and were contemporaneous with the Mono lake, Cal., 

 and Utah deposits. Now when the sea was full of water and 

 Bacillariacege deposited, there came a raising up of the 

 bottom by volcanic agency. This volcanic agency formed 

 the lava and trap that is found now all over the plain. 

 It broke out in several places but more particularly in 

 the Lassen's Peak region in California. Suffice it to say 

 the water had to escape. This it did by the Columbia 



