ACADEMY OF NATURAL SCIENCES. 163 



removed from the outcrops, while they abounded below. 

 The outcrops gave little indication of the metal-bearing 

 character of the veins. He had observed as he believed, at 

 least three distinct periods of volcanic activity in that region 

 of the Colorado and Mohave, two of which periods were sub- 

 aqueous, and the last sub-aerial. The lava-streams generally 

 appeared to have been poured out after the face of the country 

 had already assumed its present form. The volcanic outflows 

 though extensive had not materially modified the topography 

 of the country. 



Mr. Ehrenberg stated that the copper ores in the vicinity 

 of La Paz, and Mineral City, Arizona, were generally argenti- 

 ferous, sometimes giving results by assay as high as $200 per 

 ton. The ores beyond that district did not appear to contain 

 much. The quicksilver ore at the Eugenie vein contained 

 both silver and copper. 



Doctor Behr presented the following paper : 



Notes on Californian Satyrides. 



BY HERMAN BEHR, M. D. 



Chionobas Nevadensis. Boisduval, in lil/eris. 



A few specimens of this new and as yet undescribed Chionobas, were eaught 

 by Mr. Lorquin, the discoverer of the gpecies, and named by Dr. Boisduval. 

 Not possessing a single specimen of this rare species, I am not able to give a 

 diagnosis, and have only an indistinct recollection, that the species bore most 

 resemblance to the Gerontogeic, Ch. Tarpeja, a Siberian species that has al60 

 been found on the summit of the Appenines, in Italy, but that in size it is 

 superior to any Chionobas known to me. 



Sattrus Sthenele Boisd. 



Is rather common near San Francisco, where it is found in Juno. Only one 

 generation annually. 



Satyrhs Sylvestris Edwards. 



Edwards' description shows very clearly the marks by which S. Sylvestris can 

 be recognized from S. Sthenele. This species is found on grassy hills thinly 

 covered with live-oak, where its habits show a very marked difference from 

 those of its relations, by preferring the underside of oak branches to any 

 other seat, while Sthenele and Boopis almost exclusively settle on the ground. 



