28 FLOEA OF SOUTHEEN NEW YORK AND NEW ENGLAND. 



similar to the Glen Cove shale, but its outcrop has not been located. The material 

 is abundantly represented in the morainal deposits of the vicinity, and practically 

 the same conditions prevail at the other two localities. In no instance can even 

 the clay exposures be definitely identified as outcrops, but they apparently are 

 isolated masses which have been torn from the underlying beds and deposited as 

 great clay bowlders in the moraine. The differences between these large masses 

 and smaller ones, and between the fragments that are partly and those that are 

 wholly oxidized, are differences in degree only, and all are clearly the result of 

 glacial erosion and transportation. 



On Staten Island the clays at Kreischerville and Green Eidge contain quan- 

 tities of lignite and numerous leaf beds. At the latter locality they are in place 

 and only the surface of the exposure has suffered any disturbance. At Kreischer- 

 ville the beds appear to have been redeposited to a considerable extent, as the plant 

 remains often occur in lenses or pockets and the accompanying sandy layers are 

 conspicuously cross-bedded. Amber and charred wood, in considerable abund- 

 ance, are mixed with the vegetable debris at this locality, as recently described by 

 me in a paper on "The Occurrence and Origin of Amber in the Eastern United 



States." a 



At all the other Staten Island localities small masses of what are apparently 

 Cretaceous clays and sands occur in the moraine, but at these localities the fossil 

 leaf impressions have been found only in the accompanying ferruginous shales and 

 concretions. 



The former presence of not only the Cliffwood but also higher formations, 

 throughout the insular area, is also proved by the occurrence of Cretaceous inverte- 

 brate fossils in the moraine on Staten Island, Long Island, and Block Island, 6 in 

 addition to the well-known occurrence of similar fossils, together with vertebrate 

 remains, in place, in the Gay Head section on Marthas Vineyard, and scattered 

 morainal material at Indian Hill and Chappaquiddick. c None of these fossils, how- 

 ever, has been found anywhere in any of the plant-bearing beds, so far as I am 

 aware, and they have therefore proved of no value as correlation factors in connec- 

 tion with these deposits. The point of greatest interest in connection with them 

 is probably the fact of their occurrence at Arrochar, on Staten Island, and at Brook- 

 lyn, on Long Island, indicating a former overlap of upper Cretaceous strata in that 

 vicinity, which must have extended throughout the area now occupied by New 

 York Harbor, the East Eiver, and probably a part of the Hudson River Valley, 

 but was later entirely eroded. 



CORRELATION OF THE INSULAR AND ALLIED FORMATIONS. 



The stratigraphic position of the formations discussed in connection with this 

 monograph may be understood by reference to the following table, in which are 

 set forth the views of a number of recent authorities : 



a Am. Naturalist, vol. 39, 1905, pp. 137-145. 



fcHollick, A., Trans. New York Acad. Sci., vol 11, 1892, p. 98; ibid., vol. 15, 1895, pp. 3-5; ibid., vol. 16, 1896, pp. 11 and 16. 



cLyell, Travels in North America, vol. 1, 1845, pp. 203-206; Stimpson, Am. Jour. Sci., vol. 29, 1860, p. 145; Shaler, Bull. 

 Mus. Comp. Zool. Harvard, vol. 16, 1889, pp. 89-97; Hollick, Trans. New York Acad. Sci., vol. 13. 1893, p. 16; Bull. New York 

 Bot. Gard., vol. 2, 1902, pp. 400-401; Woodworth, Bull. Geol. Soc. Am., vol. 11, 1900, pp. 459-460; Brown, Am. Jour. Sci., vol. 

 20, 1905, pp. 229-238. 



