THE CRETACEOUS FLORA OF NEW ENGLAND 6ii 



which are open to various interpretations, the formation is every- 

 where much thinner. This is capable of more than one explanation, 

 but from a consideration of all the facts it seems probable that at 

 least the older Raritan, that is to say the Lower and Middle Rari- 

 tan of the Amboy district from the base to the top of the Wood- 

 bridge clays, the upper surface of which shows considerable erosion, 

 is a purely local deposit continental or estuarine in character, and 

 that the southwesterly extension of the Raritan represents the 

 Upper Raritan. In endeavoring to trace the Raritan eastward 

 beyond Staten Island one searches in vain in the very numerous 

 well records (Veatch listed over 900 in 1906) for the representatives 

 of the Raritan, Woodbridge, and Amboy clays, the basal beds of 

 the coastal plain in the eastern area being prevailingly sandy with 

 irregular clay lenses of no great extent. This together with the 

 paleobotanical evidence leads to the conclusion that the Lower 

 and Middle Raritan were never present east of Brooklyn, and that 

 while the Upper Raritan may have extended eastward as it did to 

 to the southwestward there is at present no evidence of such an 

 extension. If the Long Island Cretaceous were Upper Raritan, 

 the described floras are extensive enough to determine this point. 



Obviously, if the Raritan failed to extend along the north shore 

 of Long Island it was never represented on Martha's Vineyard, 

 Block Island, or the Elizabeth Islands, and this is strikingly con- 

 firmed by the lithologic character of the Upper Cretaceous in the 

 latter region and by the extensive flora, as has been recognized 

 to a more or less degree by White, Ward, and HolHck, who have 

 studied this flora. Of the 126 recorded species from Martha's 

 Vineyard and Block Island only 36 are found in the Raritan. The 

 number common to the Magothy is but 37, but these include a 

 large number of forms that are distinctive horizon markers and 

 range to higher levels in our southern states. 



According to the age determinations as outlined above, the 

 Raritan and Magothy floras are segregated in the following lists. 

 These show that the Raritan flora comprises 224 and the Magothy 

 flora 289 species (so called); 61 per cent of the Raritan flora does 

 not extend into the Magothy and 70 per cent of the Magothy flora 

 does not occur in the Raritan. A mere statistical method does 



