80 



An extensive layer of similar material was lately brought to 

 light at Baisley's pond, about two and one half miles from the 

 town of Jamaica, on Long Island. About two millions of square 

 yards of this peat were thrown out at this place, and it consists, for 

 the most part, of one species, Himantidium arcus. 



A similar deposit was discovered by the late Professor J. W. 

 Bailey, at West Point, New York, and specimens have been re- 

 ceived from Bemis' Lake, N. H. The discovery of these deposits 

 confirms the opinion of Professor Bailey, expressed at the time of 

 the finding of the West Point layer, that similar ones are to be 

 found under all our ponds and marshes. The species found in 

 the Milwaukee marl are all common freshwater ones, and are as 

 follows : — 



Making in all 31 species, of which the following are common in 

 this deposit : — 



Oocco7ieis placentula, Ejnthemia turgida, 



Cocconema cymhiforme, Gomphonema coiistrictum, 



" cystula, Pinnularia ohlonga. 

 Epithemia granulata, 



The two species, Gymatopleura elliptica and Surrirella nohilis, 

 were only found in fragments. 



