240 



a Monograph on the species of Pisidium, found in the 

 United States. Referred to the Committee on MoUusca. 



Dr. Gould introduced to the Society, Dr. Hunter, of 

 North Carohna. 



Dr. Hunter exhibited a native crystallized diamond, from 

 the gold region of North Carolina. It was the second only 

 that he had known to have been found in that State. Two 

 had been obtained within his knowledge in Georgia. 



Dr. C. T. Jackson said, he considered the discovery of 

 diamonds in this country, in the gold bearing districts, as 

 interesting, showing as it did the similarity of the deposits 

 to those of other parts of the world. He had before only 

 seen two small specimens from these districts. 



Prof. Wyman exhibited several Alligators' teeth, for the 

 purpose of showing the manner in which the new teeth 

 press upon and produce absorption of the old ones in the 

 process of dentition. This had been described in both 

 Crocodiles and Alligators. The number of teeth in this 

 animal is sixty. Prof. Wyman also exhibited pieces of 

 wood taken from the stomach of a Florida Alligator. Ii is 

 a popular notion at the South that these animals on the 

 approach of winter are in the habit of swallowing various 

 indigestible substances, such as wood, stones, &c. for the 

 purpose of filling the stomach during the season of hiberna- 

 tion. In Florida, however, they can hardly be said to hi- 

 bernate. He was inclined to think that these things are 

 swallowed by the animal accidentally in seizing its food. 

 The stomach he had found to be not so muscular as it is 

 described to be, not so much so as to give it at all the cha- 

 racter of a gizzard. 



Mr. Ayres said, that it was a very common thing to find 

 in the stomachs of fishes similar substances, even wool and 

 shells. He had frequently found them in the stomach of 

 Leuciscus pulchellus. He had seen a block of wood of the 

 size of a cubic foot taken from the stomach of a Halibut, 

 where it had apparently laid for a long time. 



