6io EDWARD W. BERRY 



their extensive flora, they are unquestionably of Magothy age. 

 Fossil plants have been found in morainal materials at a large 

 number of localities on Long Island. These are Brooklyn, Elm 

 Point (Great Neck), Mott Point (Manhasset Neck), Glen Cove, 

 Sea Cliff, Dosoris Island, Lloyd Neck, Eaton's Neck, Roslyn, 

 Oak Neck, and Montauk Point. 



While it is quite possible that some of these materials may have 

 been derived from Raritan outcrops once present to the north- 

 ward, the flora does not indicate Raritan affinities. Of the lOO 

 species listed from Long Island in Monograph 50 {op. cit.), only 

 33 have been found in the New Jersey Raritan, which is about the 

 same proportion that survives from the Raritan into the over- 

 lying Magothy formation in the New Jersey area. There is then 

 no paleobotanical evidence of the existence of the Raritan east 

 of Brooklyn. 



The probable genesis of the Raritan has an important bearing 

 on this question. The Raritan formation in the area of its type 

 development (i.e., around Raritan Bay, New Jersey, the so-called 

 Amboy district) consists of a lower, middle, and upper horizon 

 with thick, argillaceous beds, separated by well-defined sand beds 

 from 35 to 50 feet in thickness. The Raritan fire and potter's 

 clay at the base is about 35 feet thick. The middle or Wood- 

 bridge clays range from 30 to 60 feet in thickness, while the upper 

 clays (South Amboy fireclay and stoneware clay) are about 50 

 feet in thickness. These all carry fossil plants. In discussing this 

 flora the writer has demonstrated' that it shows a remarkable 

 cleavage into an older flora (Lower and Middle Raritan) and a 

 younger flora (Upper Raritan), from the latter of which a large 

 number of the forms common to the Magothy take their origin. 

 In tracing the Raritan southwestward across New Jersey, Delaware, 

 and Maryland to the Potomac River valley it has been found 

 impossible to recognize the well-marked divisions described in the 

 Amboy district. The massive clays of the latter are replaced 

 within a dozen miles by prevailingly arenaceous deposits, and with 

 the exception of certain well records, e.g.. Fort Dupont, Delaware, 



I E. W. Berry, "The Flora of the Raritan Formation," Bull. 3, Geol. Siirv. of New 

 Jersey, 191 1. 



