380 DARTON GREEN POND, N. J., TO SKUNNEMUNK MT., N. Y. 



are showings of iron ore at several points, but I saw no exposures of the 

 associated rocks. 



. On the western slope of Pine hill, which lies half way between Corn- 

 wall Station an-d Monroe, I have recently discovered several small 

 outcrops of the formation. This locality is about half a mile northeast 

 of Highland Mills station of the Newburg branch of the Erie railroad- 

 The beds lie on a great mass of Longwood red shales and, as at Cornwall 

 Station, there are streaks of limonite along the contact. The rock is ai 

 deeply decomposed -sandy limestone of light buff color, and it contains 

 a fairly abundant fauna. Orthis oblata, Strophomena rhomboidalis, Spirijer 

 macropleurus were the most clearly marked species noticed, but frag- 

 ments of several other forms were observed. The thickness is about 30 

 feet, but there is no complete section exposed. The overlying formation 

 is Monroe shale containing occasional fossils. The relations at this 

 locality are shown on the right-hand end of section III, plate 17. 



There is a small showing of purplish buff shale half a mile south of 

 Highland Mills station on the road to Central Valley, which appears to 

 be an extension of this area, but no fossils were found. In the surround- 

 ing region and to the southward there is a heavy drift covex. On the 

 opposite side of Skunnemunk mountain there occur the Helderberg 

 limestones mentioned on page 377 and shown in figure 2. The outcrop 

 is under the western face of the southernmost' area of Oriskanyquartzite, 

 and the thickness of the bed is not over a yard or two. The rock is a 

 thin bedded, dark blue gray, moderately pure limestone and the fossils 

 are rare and poorly preserved. They were examined by Professors Hall 

 and Whitfield, and it was found, that they were undoubtedly Upper 

 Silurian in age. A ventral valve of Spirijer cyclopterus and some crinoid 

 stems were the best j^reserved remains, but S. macropleurus and Orthis 

 oblata were less clearly exhibited. The beds lie on the light blue gray, 

 glimmering limestone of supposed Cambrian age, but the contact was 

 not observed. 



Careful search was made for the extension of this Helderberg lime- 

 stone under the other quartzite areas northward, but owing to drift and 

 debris no exposures were found. 



The next exposure southward was discovered in 1889, on the western 

 slope of Bellvale mountain, at a point half a mile north of the road from 

 Greenwood lake. The outcrop is a very small one, and is in an old field 

 near the bottom of the slope. The rock is a dark gray, moderately pure 

 limestone. Only one fossil was found, and that was a fragment of a 

 badly crushed shell, but it had a punctate surface, which strongly sug- 

 gested Strophonella piinctulifera, Conrad. It was clearly not a fragment 

 of coral, the surface of a triboUte, nor a cast of Bucania punctiferons. The 



