1869.] 



303 



[Greenleaf. 



This dredging is very rich in rare and beautiful forms. I have 

 carefully examined four slides and inserted in the following list 

 every thing of interest that 1 found. 



Bacteriastrum furcatum. 

 " nodulosum. 



' ' hyalinum. 



Hyalodiscus stilliger. 

 Surirella Febegeri. 

 Eupodiscus argos. 



" radiatus. 



Amjjhiprora elegans. 

 Cyclotella — various and new. 

 Triceratium favus — beautiful 



specimens. 

 Triceratium punctatum. 

 Biddulphia rhombus. 



" Baileyii and valve. 



' ' Tuomeyi. 



" radiatus. 



Pleurosigma baltica. 



" angulata ? 



" fasciola. 



' ' strigosum. 



Amphitetras ornata. 

 Campylodiscus cribrosus. 

 " Hodgsonii. 



Navicula musca. 



Navicula perraagna. 



" ovalis. 



' ' spectabilis. 



" prsetexta. 



' ' punctulatum. 



" didyma. 

 lyra. 



" Bohemica. 



" incomperta. 

 Auliscus sculptus. 

 Actinoeyclus Ralfsii. 

 Omphalopelta. 

 Plagiogramma. 

 Cocconeis, new. 

 Amphora, frequent. 

 Rhizosalenia, broken, no whole 



specimen. 

 Actinoptychus undulatus. 

 Nitzschia sigmoidea. 

 Coscinodiscus lineatus. 



" in great variety. 



Doryphora amphiceros and varie- 

 ties. 

 Heliopelta. 



March 17, 1869. 



Vice President, Dr. C. T. Jackson, in the chair. Thirty-nine 

 members present. 



Mr. Thomas GaiSeld offered some remarks upon the com- 

 parative capacity of different kinds of colored and colorless 

 glass for passing the actinic rays of light. 



Mr. T. T. Bouve read a letter from a gentleman in Hull, 



