Lawson. I 



Post- Pliocene Diastrophism. 



'45 



Resides these, Mr. W. J. Raymond, of the University of Cali- 

 fornia, has kindly placed at the writer's disposal the following list 

 of fossils, which he lias collected from the same section, and identi- 

 fied:— 



*Saxidomus gracilis Gld. 



Tapes Staleyi Gabb. 



*Natica Lewisii Gld. 



*Solen sicarius Gld. 



In the same series Dr. Cooper records the occurrence of the 

 following species in the vicinity of the Twelve Mile House and 

 Twelve Mile Creek, a few miles to the eastward of Mussel Rock: — 



*Chrysodomus tabulatus Baird PI. 



*Cryptomya californica Conrad PI. 



Galerus filosus Gabb PI. 



*Siliqua patula Dixon PI. 



*Macoma edulis Nuttall PI. 



*Macoma inquinata Deshayes PI. 



*Modiola recta Conrad PI. 



*Nassa fossata Gould PI. 



*Nassa mendica Gould PI. 



*01ivella biplicata Sovverby PI. 



*Purpura canaliculata Duclos PI. 



*Saxidomus gracilis Gould PI. 



*Solen sicarius Gould PI. 



*Standella californica Conrad PL 



*Tapes staminea Conrad PI. 



In a small canon about half way between Mussel Rock and 

 Twelve Mile House, a section of these Merced beds may be 

 observed, at about, probably, the middle of the series, in which 

 trunks of trees are imbedded which project out from the vertical banks 

 into the canon. With these trees are associated cones, which Pro- 

 fessor Greene informs me are those of Pseudotsuga taxifolia (Doug- 

 las spruce). The timber of these trees is well preserved, and as 

 erosion exposes the trunks, the people of the neighboring ranch cut 

 them into firewood. In vertical section above this Pliocene kindling 



* Still living. 



