49 



point, in the midst of the wide tract of the slate of Sussex county, 

 it ranges southwestward, following nearly the valley of the Pau- 

 linskill creek to its mouth, and terminating in another wedge- 

 shaped point on Cobus creek, in Pennsylvania, about- a mile and 

 a half beyond the Delaware. It has the form of a long, con- 

 tinuous, and nearly straight belt; varying between one and two 

 and a half miles in breadth. The only conspicuous irregu- 

 larity in its margin, is where a long narrow tongue of the over- 

 lying slate intrudes itself into this tract northwest of Newton, 

 following the immediate valley of the PauHnskill for several 

 miles. 



The physical features of this extensive range of the limestone, 

 are those of a valley deriving its outlines from an active denuda- 

 tion of the rocks along an axis of elevation which traverses it 

 nearly centrally from one extremity to the other. 



On the opposite or southeastern side of the main zone of pri- 

 mary rocks which crosses the State, we meet with the limestone 

 extending at somewhat interrupted intervals in a long narrow 

 band, in the bed of that great continuous valley which separates 

 the main chain of the Highlands longitudinally into two nearly 

 equal wide belts of hills. 



Taking up this range of the limestone at its northeastern 

 extremity, the first narrow band which we encounter, is be- 

 tween the outlet of Long Pond, and the outlet of Macapin 

 Pond, along the eastern base of the Lonsr Pond Mountain. This 

 exposure of the rock is about three and a half miles in length, 

 commencing about two and a half miles north of Macapin Pond. 

 Another very small patch of the limestone presents itself about 

 one mile to the northeast of the head of Green Pond. Both 

 this and the former locality, exhibit a considerable quantity of 

 fossil marine shells in the rock, belonging, however, to but a 

 limited number of species. Elsewhere, throughout the State, 

 this limestone formation is singularly deficient in organic re- 

 mains ; and consequently, these isolated tracts derive consider- 

 able interest to the geologist from their fossiliferous character. 



Extending our researches through the same general valley, we 

 again come upon the limestone, about two miles to the southwest 

 of Flanders, from whence we may trace it in an interrupted belt 

 down German Valley to Clinton, and thence along the south- 



5 



