Putnam.] 



18 [October 5, 



difference between the habits of the young and old of the 

 same species. 



The "green hair" noticed by Mr. K. as found on the small 

 water turtle (Thyrosternurn Pennsylvanicum) was a con- 

 fervoid growth common on the many species of fresh water 

 turtles, and especially on the members of the family Cinos- 

 ternoidoe and other species living mostly in stagnant water. 



The observations on the use of the long nails of the feet 

 of Ptychernys he considered as a most important and inter- 

 esting fact added to our knowledge of the habits of turtles, 

 and as another most interesting example of the adaptation 

 of structure to habits. 



Mr. B. P. Mann spoke of carbolic acid as a preservative. 

 He had used two preparations successfully, viz. : 1st, 1 part 

 carbolic acid to 150 parts water. 2d, 1 part carbolic acid to 

 57 parts water. Mr. Scudder had informed him that the 

 stronger was the better preparation for the preservation of 

 the larvae of insects. 



Prof. N. S. Shaler presented the following papers by title : 

 " On the Progress of Life on the several Continents," and 

 " On the Geological Structure of the Wachusett Range." 



October 5, 1870. 



The President, Mr. Thomas T. Bouve, in the chair. Twenty- 

 three persons present. 



Messrs. Samuel How, Frank D. Millet, Edward S. Shaw 

 and Albert H. Tuttle of Cambridge, Caleb Cook and James 

 H. Emerton of Salem, Daniel T. Letteney and Charles A. 

 Walker of Chelsea, Rev. Caleb D. Bradlee, Prof. Alfred P. 



