72 JOURNAL OF THE [July, 



miles up the stream, an additional fall of fifty feet occurs. Hat- 

 field Swamp is about three and one-half miles long by one and 

 one-half miles broad, and the deposit is clay, about three feet and 

 eight inches deep, where I took the 'specimens. At Columbia 

 Bridge, four miles further, is a small patch of similar clay, per- 

 haps one hundred feet broad. 



Besides the ordinary fresh-water forms, Navicicla {Fmnularia) 

 viridis and similar species, there are found two salt-water forms 

 of Actinocycliis Ralfsii and Campylodiscus echeneis. These are 

 both common in the Hatfield Swamp clay, the Actinocycliis as 

 brilliantly colored discs, and the Campylodiscus as large, white, 

 saddle-shaped forms.' These are also both common on the coast 

 in salt water. And the first is further well known in the guano 

 at Ichaboe, at the Cape of Good Hope. 'Ihese diatoms cannot 

 be carried up the stream by the tide, as that does not reach 

 higher than ten miles above Newark, some distance below Pater- 

 son, and there intervene between the tide and the swamp more 

 than one hundred feet of falls, seventy feet of which are perpen- 

 dicular at Paterson. 



I present some of the clay, and a slide mounted to show the 

 mixture of fresh-water and salt-water forms. Diatoms having 

 originated in fresh water, they may present the same character- 

 istics when transferred to salt water, or they may change totally. 

 How this change goes on has not been determined, but the Hat- 

 field Swamp clay shows that recognized marine forms may live in 

 fresh water, and fresh-water forms have been seen living in the 

 ocean. 



PROCEEDINGS. 



Meeting of February 3D, 1893. 



The President, Mr. Charles S. Shultz, in the chair. 



Forty four persons present. 



The Corresponding Secretary presented a donation of dia- 

 tomaceous material from Mr. K. M. Cunningham, of Mobile, 

 Alabama, with an explanatory communication, dated January 

 30th, 1893, as follows : 



" I forward specimens of a new fossil marine diatomaceous de- 

 posit, with the object of putting the find upon record, and of 



