120 



furcula, clavicle, occiput, pelvis, and femur ; in short, of all the 

 bones except the scapula. 



Dr. Cabot, in conclusion, stated, that if this bird is to be named 

 as a distinct species, from these characters, and from the pecu- 

 liarities and measurements of the viscera also, he would call it 

 Clangula mergiformis. The testes of the specimen had been 

 examined under the microscope, by Prof. J. Wyman and himself, 

 but although much swollen, being half an inch in length, no 

 spermatic particles could be found. 



Dr. Charles T. Jackson exhibited some chlorophyj, or the 

 green coloring matter of plants, which he had obtained from 

 the Cochituate water. 



Dr. Jackson also gave the following result of an analysis 

 of AUophane, from Tennessee : water, 37.7 ; alumina, 

 41.0; silica, 19.8; lime, 00.5; magnesia, 00.2. This 

 mineral is essentially, as will be seen, a hydrated silicate of 

 alumina. Traces of phosphoric acid are likewise found 

 in it. 



Remarks were made by Drs. Gould, Abbot, and Durkee, 

 upon the vegetable forms, principally Diatomaceae, seen with 

 the microscope in Cochituate water. 



The Corresponding Secretary read a letter from Dr. 

 James Lewis, of Mohawk, N. Y., dated Nov. 15th, 1854, 

 accompanying a paper on Cyclas, Lymnea, &c., from which 

 the following is an extract : — 



" In addition to what I have observed respecting the variations 

 of certain Lymnece, I might say, that the effects of locality, tem- 

 perature, and other things, on the forms of shells, seem to he 

 equally apparent in other shells. I have found that all those 

 shells which abound equally in the Erie Canal and the Mohawk 

 River at this place, have local peculiarities, by which I can de- 

 termine at a glance, almost, which of the two localities a certain 

 number of shells may have been taken from. 



