292 Lower Helderberg Rocks of Port Jervis, etc. 



to the right, of roches moutonnees. Here the traveller passes 

 through a small cutting, in rock so plainly distinct physically 

 from the Cauda-galli as to raise the question whether it is 

 not the equivalent of the Schoharie grit — a problem which I 

 have never been able to solve, as the rock is unfossiliferous. 

 A small exposure of Corniferous and Onondaga limestone 

 comes into view along the eastern shore of the Delaware ; 

 and the remaining formations, to the base of the Hamilton 

 escarpments along the western side of the valley, are buried 

 under alluvial and diluvial deposits. Port Jervis is divided 

 into "Uptown" and "Downtown" by a terrace which marks 

 the bank of a former and much larger river. 



In all this succession of strata, from the base of the Upper 

 Silurian to the middle of the Devonian, it is only, so far as I 

 know, the rocks of the Lower Helderberg, Oriskany, and 

 Hamilton groups, that yield many specimens to the paleon- 

 tologist. As my time for such work is very limited, I have 

 confined my small efforts principally to the first two of these, 

 which, with the Cauda-galli, were well enough described by 

 Mather in the '"Geology of the First District," pages 332 and 

 333, as follows. "The limestones of the Helderberg Divis- 

 ion, in the Mamakating valley, from Carpenter's Point on the 

 Delaware to Kingston, are all upturned, and frequently at a 

 pretty high angle. In the township of Deerpark, Orange 

 Co., they form a narrow range of hills or low mountains, 

 sometimes sinking almost to the level of the Neversink val- 

 ley, and at others, rising to one-third or one-half the eleva- 

 tion of the Shawangunk. They are always narrow, and 

 generally close to the base of the last named mountain." 

 Carpenter's Point is a suburb just outside of the corporate 

 limits of Port Jervis, and Deerpark is the name of the town 

 in which the latter is situated. "Fossils were rarely seen in 

 the limestones of the Helderberg division south of Rochester" 

 (near Kingston in this valley), "except in those of the moun- 

 tain east of Carpenter's Point, and at this place they were 

 extremely abundant. The specimens of trilobites were so 



