1871.] 305 [Dwight. 



Dr. Warren, a diatom which has not before been found out- 

 side of New Hampshire and Maine. 



Mr. Greenleaf remarked that his types came from Bemis 

 Lake, N. H. 



June 21, 1871. 



The President in the chair. Twenty-nine persons present. 



Mr. W. H Dall made some remarks on the geography of 

 the Aleutian Islands, which have been as yet only imper- 

 fectly explored, and stated that an expedition to them in 

 charge of the Coast Survey was intended, with which he was 

 to be associated. Mr. Dall also referred to the differences 

 between the walrus of the Atlantic and Pacific Coasts, which 

 he considered as varieties of one species, and described the 

 habits and commercial importance of these animals. 



The President read an article on Silica. He showed the 

 almost universal presence of this mineral, its beauty under 

 many forms, and its great economic value. He exhibited a 

 beautiful crystal globe, six inches in diameter, of Japanese 

 manufacture, which Mr. Thos. Gaffield had lent him for the 

 occasion. 



Dr. Chas. T. Jackson called attention to the occurrence of 

 crystal globes in the Druid Mounds of England, which are 

 of a*n oblate-spheroidal form, and about the size of an orange. 

 He thought the Druids must have obtained the material from 

 Japan or other equally remote place, as no locality for it is 

 known nearer England. 



Dr. Thos. Dwight gave a brief account of his work in the 

 preparation of the skeleton of the whale for the Society's 

 Museum. 



The whale is an example of the Balcenoptera musculus, or Physa- 

 lus antiquorum, although there are so many small peculiarities that 

 many observers would he inclined to make it a new species. 



PROCEEDINGS B. S. N. H. — VOL. XIV. 20 APRIL, 1872. 



