Trans. N. V. Ac. Sa. 150 ^'^ay 21, 



was also described. The veins ia this region were first opened dur- 

 ing the past summer. 



The GiUis mine is the only one with a history, having been reported 

 upon by Prof. Jackson at the close of the war. 



The country rock is slate, which dips east, wilh a strike north 10 

 east. Dykes occur, and evidences of the inetamorphism of the slates, 

 which, along the line of contact, contain metallic copper. The dykes 

 themselves are sometimes strongly impregnated with sulphuret of 

 copper and metallic copper, averaging a content of two per cent., at 

 one place visited, in metallic copper. Epidote is also largely found 

 along the centre of the ridge, or line of contact. 



The quartz veins in this region carry carbonate, silicate, and sul- 

 phuret of copper, and generally strike north 10° east. One vein, 

 however, which Dr. RiCKETTS inspected, about 2% feet in width, 

 crosses this direction at right angles, dipping to the north. 



The first-class ore from this vein yields forty per cent, of copper and 

 25 ounces of silver to the ton. A large number of specimens from 

 these veins were exhibited. 



These remarks were briefly discussed by the President, Dr. 

 RiCKETTS, and others. 



May 2T, 1883. 



Lecture Evening. 



The President, Dr. J. S. Newberry, in the Chair. 

 'J1ie large Hall was filled by the audience. 



Prof. D. S. Martin read by title the two following papers : by 

 Prof. Edward V. Martens, communicated by Mr. Thomas Bland, 



description of two species of land shells from PORTO RICO 



Cistula consepta, nov. sp. 

 Chondropoma Tortolense — Pfr., var. major, 

 and by Thomas Bland, 



DESCRIPTION OF TWO NEW SPECIES OF ZONITES FROM TENNESSEE — 



Zonites Wheatleyi, nov. sp. 

 ' Zonites petrophilus, nov. sp. 

 Prof. John K. Rees, of the Observatory of Columbia College, 

 New York City, then delivered the monthly lecture, on the sub- 

 ject of 



THE GREAT TELESCOPES OF THE WORLD. 



