478 NEW YORK STATE MUSEUM 



tion originally; the great Stromatopora-like bodies of Hoyt's 

 quarry, four miles west of Saratoga, occurring in it."^ The reasons 

 for this correlation were given more fully by Mr Walcott at a 

 later date.^ 



On the Geologic map of New York the line of division between 

 the Potsdam and Calciferous at this locality is represented as fol- 

 lowing the highway with Calciferous on the western side. It was 

 found, however, that from the foot of the bank on the eastern side 

 of the road for 45 feet to a ledge seen on the western side of the 

 road the rocks contain specimens of Lingulepis acumi- 

 nata Con. associated with fragments of Potsdam trilobites. The 

 old Hoyt quarry is in the midst of this 45 feet and gives the fol- 

 lowing section: 



Feet 



12D1 Massive impure limestone in lower part of 

 quarry containing specimens of Lingulepis 

 acuminata Con. and trilobites. 10=10 



D^ Not well exposed. 2=12 



D^ Massive rock in layers, the upper part containing 

 Lingulepis and trilobites. 44^16^ 



The Cryptozoon stratum is light gray, strongly calcareous 

 and contains large numbers of this fossil; some of them were elon- 

 gate, others somewhat circular and one by the side of the road had a 

 diameter of 2 feet, 2 inches. This stratum is exposed by the side 

 of the road just north of the three corners a short distance north 

 of the Hoyt quarry and then is finely shown for some distance in 

 the field to the northeast. The layer immediately below the 

 Cryptozoon one in this field contains specimens of trilobites 

 and other fossils. 



In the southern part of Greenfield township not more than J 

 mile northeast of the three corners north of the Hoyt quarry and 

 2j miles northwest of Saratoga Springs are three cuts along the 

 Adirondack railroad in the Potsdam sandstone. The most eastern 

 one (12C), where the east and west highway crosses the railroad, 

 shows a massive stratum of white quartzose sandstone varying 

 from I foot, 9 inches to 2 feet in thickness. There are also shaly 

 layers in which are fucoidal markings. 



^Science, 1884, 3:137. 



»U. S. geological survey, bul. 30, 1886, p. 21, 22, and ibid, bul. 81, p. 346. 



