NORTHERN END OF THE HELDERBERG PLATEAU 59 



19 Streptelasma striatum Hall (rr) 



20 Chaetetes colliculatus Hall (rr) 



21 Favosites conicus Hall (rr) 



22 Lingula centrilineata Hall (rr) 



23 Favosites helderbergiae Hall (r) 



24 Stropheodonta punctulifera (Con.) Hall (rr) 

 C 6 At the top of the second terrace, about If miles southwest 



of High point, on the farm of Hiram Clickman, is a ledge of mas- 

 sive rock, frequently exposed about the edge of the hill, composed 

 of the Becraft limestone and Oriskany sandstone. The northern 

 end of the hill was partly covered. 10 feet of the Becraft lime- 

 stone was found, but it is probably somewhat thicker, and the 

 Oriskany sandstone jrests immediately on top. The contact is 

 finely shown at several places in the woods at this locality,, the 

 sandstone resting on the massive limestone, so that there are no 

 beds of shaly limestone between these formations, as at Schoharie 

 and Howe's cave. The limestone is light gray and rather crystal- 

 line, with the usual lithologic characters of the Becraft. 



C 7 The Oriskany sandstone is rather dark gray, weathering to 

 a brownish color, quite calcareous, and contains many specimens 

 of fossils. The thickness varies from If to 2 feet. 



1 Rensselaeria ovoides (Eaton) Hall (c) 



2 Spirifer arrectus Hall (c) 



3 S. arenosus (Con.) Hall (c) 



4 Eatonia peculiaris (Con.) Hall (r) 



5 Bhipidomella musculosa (Hall) H. & C. (?) (r) 



6 Metaplasia pyxidata (Hall) H. & C. (r) 



7 Hipparionyx proximus Van. (r) 

 ,8 Meristella lata (Hall) H. & C. (rr) 

 There are frequent exposures of these two formations along the 



highway running southeast to the Indian Ladder road, and at 

 various places one or the other forms the bed of the road for a 

 distance of several rods. , 



About 3>| miles southwest of Altamont, on the road from Alta- 

 mont to Knox, is a conspicuous ledge of the Pentamerus 

 limestone (11 A 3 ), to the east of the road, which at this 



