Blake.] 30 [October 3, 



deposition of the boulder drift, and that the subsidence went on until 

 the beds were depressed to about one hundred feet below the present 

 water line, this being the amount of sinking indicated by the upper 

 level of the stratified drift material at other points in this region. 



The most interesting feature in the evidence afforded by these beds 

 is the fact that the physical conditions during that time denoted by 

 the term Drift Period, were far from uniform, thereby showing that 

 the division of the glacial epoch into several stages, which has been 

 pointed out by Jameson and others, from the evidence found in 

 European drift, is to be recognized also in American deposits of the 

 same period. 



About one hundred specimens were procured ; the most of these 

 were well preserved fragments ; several quite perfect specimens were 

 found, and there is no doubt that careful digging will furnish individ- 

 uals of all the species occurring in the beds in a satisfactory state for 

 determination of the species. 



The author has hesitated in attempting to give a list of species 

 from his imperfect collection, as this work should be deferred until 

 ample materials have been accumulated. The following brief list will 

 give some idea of the character of the remains Imbedded in the sec- 

 tion examined. 



Leda. Two specimens. 



Modiola discrepans Say. Several specimens. 



Mya truncata Linn.? " " 



Mesodesma arctata ? Very doubtful. 



Nucula sapoiilla ? 



Panopea arcticn Gould? 



Saxicava distorta Say. 



Five or six specimens of Lamellibranchlata not identified. 



Crustacean remains, plentiful but very fragmentary. 



Dr. Charles T. Jackson read the following 



Note on the Occurrence of Gold with Cinnabar in the 

 Secondary or Tertiary Rocks. By William P. Blake. 



Since noticing in a general way the association of gold with cinna- 

 bar In the modern strata of the Coast Mountains of this State,* I 

 have received some interesting Illustrative specimens from Colusa Co.f 

 In these, native gold exists In visible grains, implanted in the midst 



* Notes on the Geographical Distribution and Geology of the Precious Metals, 

 etc. Transactions of the California State Agricultural Society, for the years 1864 

 and 1865. p. 361. 



t From Mr. Goldsworthy, of Colusa. 



