122 NEW YORK STATE MUSEUM 



north at an angle of 30° is a bed of alternating layers of quartz 

 pebbles and clay. The pebbles crush easily to a white powder. 

 Associated with this clay is a bed of kaolin, but the exact rela- 

 tions of the two deposits are not known. Kaolin also crops out 

 from under the gravels on the west shore of Hempstead Harbor. 

 Carpenter's clay resembles that of Cretaceous age found on Staten 

 Island, but its age has yet to be proven. The sandstone frag- 

 ments found in the clay across the inlet are found along the shore 

 of it to Carpenter's clay, but none are found in it. Dr. Merrill 

 has found plant remains in this clay, but they were not suffi- 

 ciently well preserved for identification. ( See paper previously 

 cited.) A microscopic examination of the clay revealed the pres- 

 ence of the following diatoms; all freshwater forms. 



Melosira granulata ( Ehr. ), Ralf s. 



Stephanodiscus Niagara (Ehr.), 



Diatoma hyeonale (?) K. B. 



On Center Island in Oyster Bay we find the most western of 

 a series of clay beds which bear a great similarity to each other. 

 The others are on West IsTeck, at Fresh Pond and on Fisher's 

 Island. The clay on Center Island consists of two kinds, a lower 

 bluish clay and an upper brown sandy clay. Overlying this latter 

 is a stratified sand. The layers of clay undulate in several direc- 

 tions. Dr. Merrill mentions the occurrence, one mile north of 

 this clay pit, of a bed of white fire clay at a depth of 25 feet 

 under the drift and sand. The only organism thus far met in 

 this clay is one species of diatom, viz.: Stephanodisous WiagaroBy 

 and a curious spiny hair. 



At Jones' brick yard on the east shore of Cold Spring Harbor 

 is a thick deposit of clay. The lower portion is tough and con- 

 tains little sand. The upper portion is much more sandy and of 

 a brown color. ' The clay bank is over 100 feet in height and the 

 layers have crumpled on a large scale by the pressure of the 

 advancing ice sheet. A layer of diatomaceous clay occurs in th 

 upper portion of the clay bank, and its position is shown in the 

 following section given by Merrill : (1. c.) 



" Till" and stratified drift 10 feet. 



Quartz gravel , 45 " 



Ked and blue " loam " or sandy clay 20 " 



Diatomaceous earth 3 " 



