16 FLORA OF SOUTHEEN NEW YOEK AND NEW ENGLAND. 



Nevertheless he gives evidence further on of accurate powers of observation and 

 an ability to draw conclusions from facts which would do credit to modern investi- 

 gators. Thus in discussing the formation of Long Island he continues: 



A more probable opinion is, that Long Island and the adjacent continent were, in former days, contiguous, 

 or only separated by a small river, and that the strait which now divides them was formed by successive inroads 

 of the sea, from the eastward and westward, in the course of ages. * * * 



Between Long Island and the continent there are several shoals, with rocks scattered over them, which are 

 apparently sunken or wasted islands. These remains of what was, probably, in former days, upland of as great 

 height as the neighboring islands afford strong evidence of the leveling power of the waves. 



Nearly all who subsequently investigated the geology of the region recognized 

 that the extensions of the Coastal Plain strata of the mainland were probably repre- 

 sented on Staten Island, Long Island, and the islands to the eastward, but at first 

 with poorly defined or erroneous conceptions of their geologic age or stratigraphic 

 relations. 



In 1823 John Finch read a paper before the Academy of Natural Sciences of 

 Philadelphia, entitled "Geological Essay on the Tertiary Formation in America," a 

 in which the Raritan, Staten Island, Long Island, and Gay Head clays are referred 

 to the Tertiary period. 



In 1824 Edward Hitchcock, in his " Notices on the Geology of Marthas Vineyard 

 and the Elizabeth Islands/' 6 remarks that "Long Island, in those places where I 

 have seen it, is unquestionably very similar in its geological structure to Marthas 

 VineyUrd, and probably belongs to the same era/ 7 while further on he concludes 

 "that the Vineyard and Nantucket are the continuation of that extensive formation, 

 hitherto called Alluvial, of which Long Island has been regarded as the north- 

 eastern limit." 



About 1825 the studies of Lardner Vanuxem and S. G. Morton resulted in an 

 effort to differentiate the late formations of eastern United States, and in a paper 

 by the latter entitled "Geological Observations on the Secondary, Tertiary, and 

 Alluvial Formations of the Atlantic Coast of the United States of America, c he 

 mentions Manhattan Island, Long Island, Marthas Vineyard, and Nantucket as 

 included in the Tertiary, although the equivalency of certain of the New Jersey 

 strata with the Cretaceous of the Old World is recognized. 



In 1837 and 1838 William W. Mather, in the First and Second Annual Reports 

 of the New York State Geological Survey , d mentions the clays and sands of Staten 

 Island and Long Island, but with very indefinite allusions to their probable geological 

 relations. In regard to the Staten Island exposure he merely says that it seems to 

 be "similar in its general characters to that of Cheesequake and Matavan Point, on 

 the Jersey shore, and it appears to have a similar geological position;" while in 

 regard to the clays of Long Island he remarks that "they have the external charac- 

 ters of potter's clay," but he refers them to the Tertiary. 



In 1843, in his final report, e Mr. Mather arrives at more definite conclusions in 

 regard to the last-mentioned strata and says: 



a Am. Jour. Sci., vol. 7, 1824, pp. 31-43. 



b Ibid., pp. 240-248. 



c Jour. Acad. Nat. Sci. Philadelphia, vol. 6, pt. 1, 1827, pp. 59-71. 



d Assembly Doc. No. 161, February 11, 1837; ibid., No. 200, February 20, 1838. 



«Nat. Hist. New York, pt., 4; Geol., pt. 1; Geol. 1st Geol. Dist.,p._248. 



