152 Geological Society :-~~ 



GEOLOGICAL SOCIETY. 



[Continued from p. TJ.~\ 



February 25, 1874.— John Evans, Esq., F.R.S., President, in the 



Chair. 



The following communication was read : — 



" Note on the occurrence of Sapphires and Rubies in situ with 

 Corundum, at the Culsagee Corundum Mines, Macon Co., North 

 Carolina." By Col. C. W. Jenks. 



The mine described in this paper is in a hill situated about 

 nine miles east of Franklin, the chief town of Macon County, rising 

 about 400 feet above the valley. The hill is a boss of serpentine 

 protruded through the surrounding granite. The corundum occrrs 

 in five nearly parallel veins, cropping out for about a mile along the 

 steep side of the hill in a direction N.E. and S.W. The veins all 

 dip to the S.E. about 45°. They are thin at the surface, but widen 

 out as they descend, the thickness of the vein in the deepest working 

 (75 feet) being about 10 feet. They consist of a mass of chlorite, 

 Jefferisite, and corundum, the latter forming from one third to one 

 half of the mass, and occurring in crystals imbedded in the other 

 minerals. The author gives a list of several minerals which also 

 occur in the veins, including two new silicates, which Prof. Genth 

 has called Kerrite and Maconite. Analyses of some of these minerals 

 and of the serpentine rock are appended to the paper. Some of 

 the crystals of corundum we'gh as much as 300 pounds. The 

 corundum is crushed and used for grinding and polishing stones, 

 glass, and metal; about 200 tons have been extracted from the 

 mine. The colour of the crystals is very variable ; and some of them 

 show different colours in different parts. Many rubier and sapphires 

 have been already procured and cut for setting. 



March 11th, 1874. — John Evans, Esq., F.P.S., President, 

 in the Chair. 



The following communications were read : — 



1. "On the relationship existing between the Echinothuridce, 

 Wyville Thomson, and the Perischoechinidce, M c Coy." By R. 

 Etheridge, Esq., jun., F.G.S. 



In this paper the author referred in the first place to the peculiar 

 characters of the genera Calveria and Phormosoma, "Wyville Thom- 

 son, and especially to those in which they approach the Cretaceous 

 genus Echinoihuria, S. P. Woodward, and which led Prof. Wyville 

 Thomson to include these three forms in his group Echinothuridae. 

 He remarked that an overlapping of the interambulacral plates, 

 more or less like that occurring in these three genera, is met with 

 also in Archceocidaris, M c Coy, and Lepidechinus, Hall, belonging to 

 the group of palaeozoic Echini which M c Coy proposed to call 

 Perischoechinidae, and which is characterized by the presence of 

 more than three rows of plates in the interambulacral areas. As 



