Stodder.] 182 [November 11, 



extent, and furnishes crystals and masses of mica of much larger 

 size. Some of the mica crystals exceed a foot in diameter, and are 

 of a quality suitable for use in the arts. Only a small excavation 

 has yet been made, but the abundance of the mica indicates that the 

 mine may prove to be very valuable. A few crystals of beryl have 

 been found which are similar to those of South Royalston, and if the 

 mine should be extensively worked it will undoubtedly yield many 

 fine crystals of beryl. 



The Custodian announced the bequest of the late Mr. F. 

 P. Atkinson of his collection of birds, eggs, and insects to 

 the Society. 



Section. of Microscopy. November 11, 1874. 

 Mr. Bicknell in the chair. Twelve persons present. 



Mr. Stodder read an account of a preliminary examination 

 of mud from oyster beds in the harbor of Charleston, S. C, 

 collected by Prof. John McCrady. 



Preliminary examination with the microscope shows that it con- 

 tains Diatoms, but only in a small proportion of the mass, which is 

 made,up almost entirely of apparent organic matter in a -state of de- 

 composition, with some sand. I have found in it many pollen grains 

 of Coniferae and one Polytlialamia. The Diatoms, so far, are two or 

 three species of Pleurosigma, one of Nitzcliia, one of Amphora, two 

 or more of Navicula — some of each containing the endochrome, and 

 many of the Navicula in particular looking fresh and' living — two 

 specimens indeed were alive and moving freely. There was one ex- 

 ample of Biddulphia Baileyi W, S. (= Zygoceros mobilensis Bai- 

 ley), with endochrome, showing that this was its native locality. 

 The shells of this species have usually been found in deeper water in 

 the Gulf and Gulf Stream. There are a few Melosira (Orthosira 

 W. S.), but the most abundant form is Tryblionella punctata W. S., 

 very small, and all empty shells. As yet I have found none of the 

 circular and angular forms so frequent in the waters of Charleston 

 harbor, where the forms before mentioned are also plenty. 



