GEOLOGY AND^GEOGRAPHT OF CLAY DEPOSITS 123 



Yellow and red stratified sand 20 feet. 



Red plastic cloy , 20 " 



Brown plastic clay 25 " 



Total 143 



" The bed of diatomaceous earth is of undetermined extent, 

 and appears to be replaced a little to the east by a blue clay, 

 which, however, contains some diatoms. It is undoubtedly equiv- 

 alent to the bed of ochre which overlies the sand throughout the 

 remainder of the section." 



The following diatoms, all fresh- water species, occur in it : 



Melosira granulata (Ehr.) Ralfs, 



StejphanodisGus Niagarce (Ehr.) 



Epithemia turgida (Ehr.) Kutz. 



JEnoyonema ventricosum^ Kutz. 



Cymbella delicatula^ Kutz. 



Cymbella cuspidata, Kutz. 



Navicula viridis, Kutz. 



" GOGoneifornds, Greg. 



'• major, Kutz. 



" variams, Greg. 



" lata, Breb. 



Eunotia monodon, Ehr. 



Gorrvphonema GapitatuTu, Ehr. 



Stauroneis PhoeneGenteron, Ehr. 



Fragilaria construans, Grun. 



Synedra affinis, K. B. 



Campyloneis Grevillei var. Regalis. 



TriGeratium trifoliatium. 



The Melosira and 8tej)hanodisGus are present in countless num- 

 bers. Only two specimens were found of the TriGeratium, and 

 Dr. D. B. Ward,* of Poughkeepsie, who has also given me much 

 aid in the identification of my material, informs me that this 

 species is very common in the diatomaceous earth from Welling- 

 ton, New Zealand, but he has never heard of its occurrence 

 before in America.* Sponge spicules are not uncommon in 

 Lloyd's Neck diatomaceous earth, and several forms are figured. 

 Samples of the red and orown clay from the section given 

 above were examined, but no organic remains were found in them. 



* Since this report was sent to press the writer has been informed of the discovery by Mr. 

 Lewis Woolman of this same species in certain New Jersey deposits. 



