170 PROCEEDINGS OF THE CALIFORNIA 



Prof. Brewer gave an account of recent explorations in the 

 Sierra Nevada, by the party connected with the State Geolo- 

 gical Survey. The exploration extended from Kern River to 

 the Yosemite Valley, and was peculiarly rich in scientific re- 

 sults. The crest of the chain is very high ; along the whole 

 of this distance, the high peaks, rising to above 13,000 feet, 

 the culmination being between the sources of the Kern and 

 Kings Rivers, where there are a number of peaks over 14,000 

 feet, and one about 15,000 feet in height. Along the whole 

 of this, there are abundant traces of glaciers, some of the 

 morains of which are truly gigantic, far surpassing anything 

 else of the kind yet found in the State. The canons of all 

 of all the principal streams are very deep and abrupt. 



The Big Trees or Sequoias, were found over a large area, 

 extending perhaps 25 miles along the western slope, along 

 the tributaries of the San Joaquin, Kings, Kaweah, Tule and 

 Kern Rivers. The amount of snow in this part of the sierras, 

 is apparently very much less than usually occurs. 



Prof. Wm. P. Blake, read the following: 



Note on the discovery of Fossils in the Auriferous Slate 



formation of the Mariposa Estate, California, and 



the probable geological age. 



BY PBOF. WM. P. BLAKE. 



During a recent visit to the Mariposa Estate, Mariposa County, my attention 

 was called to some organic remains in the slates, near Bear Valley, by Miss 

 Errington, a lady who takes an enthusiastic interest in the sciences of geology 

 and mineralogy, and has for some time past, been seeking for fossils in the 

 gold formation of that neighborhood. One of the specimens was the cast of 

 a bivalve shell, and appeared to me to be a Plagiosloma. On further search, 

 we found other specimens, some of which much resemble Inoceramus, to which 

 I am inclined to refer them. Certain long tubular cavities in the slates, ; mark- 

 ed with heavy lines, and slightly converging, ;eemed to be casts of long, near- 

 ly cylindrical shells, possibly Nerincea. These forms would indicate a Jurassic 

 or Cretaceous age for the formation. I propose to submit these specimens to 

 a competent Paleontologist, at the East, for examination, and to dedicate one 

 of the species, if new, to Miss Errington. 



