154 Scientific Intelligence. 



Hills and other portions of the interior, and much effort to ascer- 

 tain the limit on Long IslaDd between the drift and the Tertiary 

 beds beneath, coincides with that of Mr. Merrill. The height 

 above the sea-level of the Tertiary (or Cretaceous) clay beds of 

 the north shore of the island north of the West Hills of the cen- 

 tral line, and their occurrence near the centre of the island in 

 Bethpage at a level not far from a 100 feet, just south of the high 

 " West Hills " lead naturally to the inference that boring would 

 find the Tertiary at a height of at least 100 to 150 feet over much 

 of the higher part of this land. The summit region of the West 

 Hills and the long slopes either side have their cobble stones and 

 some larger bowlders, along with the usual pebbly gravel, but 

 nothing that would suggest by itself, as Mr. Merrill implies, a 

 terminal moraine, or its limit. Still great bowlders occur along 

 the shores, especially the northern, and on some other high 

 elevations. Mr. Merrill states that one of gneiss on Shelter 

 Island (in Peconic Bay) contains over 9000 cubic feet. The 

 yellow pebbly gravels that cover the larger part of Long Island 

 up to 100 feet and often higher, are stratified, and Mr. Merrill is 

 disposed to make them equivalents of the pre-glacial yellow 

 gravels of New Jersey. Whether this is the case, or whether 

 they are Champlain deposits, the writer has not been able to de- 

 cide. 



The chief evidence of Cretaceous strata below Brooklyn at the 

 west end of the island mentioned by Mr. Merrill is the discovery 

 of an Exogyra costata with green sand adhering at a depth of 60 

 feet between Brooklyn and Flatlands, and an apparent strati- 

 graphical relation to the Cretaceous of Staten Island and New 

 Jersey. The author observes that the Cretaceous beds may ex- 

 tend as far eastward as Glen Cove, but that no satisfactory evi- 

 dence has yet been found of their extending farther. The occur- 

 rence is mentioned of a tooth of Carcharodon angustidens or 

 megalodon and recently of a small fossil leaf, in the clay beds of 

 Little Neck; and this is the only •paleontological evidence as to 

 the Tertiary. The character of the clays, the general absence 

 of lamination, the white and other colors, and the presence 

 of much lignite, though generally in fragments as if transported, 

 are evidence of Tertiary age, (if not of Cretaceous). But where 

 the Tertiary ends and the Quaternary begins is a difficult prob- 

 lem unsolved. 



The varying dip and flexures in the clay beds and the gravels 

 associated with them, are described, and Mather's earlier work in 

 this line referred to. This appearance of disturbance is well 

 known to occur in all the islands east of Long Island to Martha's 

 Vineyard. The flexures are described by Mr. Merrill as having a 

 strike at right angles to the advancing glacier, and the conclu- 

 sion thence drawn that they were produced by the push of the ice. 

 The bays of northern Long Island, of remarkable depth (6 to 15 

 miles) for a coast of gravel deposits and clays, are regarded by 

 the' author as a result of excavations that were made by the same 

 movement; and the .high hills severally south of the bays are 



