CALCIFEROUS GROUP. 37 



was found ; at Sage & Reed's quarry, opposite to Tripes hill ; and at the creek at Sprakcr's 

 basin, below the falls where the Ophileta eomplanata was first seen. West of the basin, the 

 layers appear in the side-hill, and by the road-side, projecting beyond the soil every few rods, 

 the calciferous layers being below them ; and thus, with little intermission, th6 two continue 

 to near Fort-Plain. 



The best exposition of these layers which came under notice, was at Canajoharie ; there 

 the rock is thicker and more extensively quarried, and the material of the birdseye limestone 

 is also in greater abundance. The upper part of the quarry shows two layers, each over two 

 feet thick, which are like those of the calciferous rock. They have undergone considerable 

 change by exposure, and their color is yellow. 



Under these, is a layer of dark color, fi^ne-granular, sparkling in parts, and mottled ; be- 

 comes somewhat olive by exposure to the air; composed of carbonate of lime and fine 

 brownish black sand : thickness two feet. 



Under this, a layer composed of the birdseye limestone with some black shale, the latter 

 disposed in waved lines often crossing each other, but forming somewhat parallel divisions, 

 and arranged in accordance with the layers. As the slate is small in amount comparatively,- 

 this layer would make a handsome marble ; but to show the variegated appearance, it would 

 require to be sawed obhquely. This particular layer greatly resembles many of those which 

 belong to the Black river limestone in Lewis and Jefferson county. It is rare on the Mohawk, 

 not remembering to have seen it but at Canajoharie. Thickness six feet ; color grey dove. 



Under this layer, there is one which shows numerous accretions, of all forms, but small, 

 having the same mineral character as the one above, the parts united by crystalline limestone 

 of the same color, and the accretions frequently showing a slight covering of green carbonate 

 of copper. This is the most fossiliferous part of all the layers, containing the fossil No. 1, 

 and fragments of a trilobite which probably belongs to an illeneus or isotelus. 



The layers below these upper ones show but little of the birdseye limestone, the calciferous 

 part with the shale predominating, the rock being uncovered for about twenty feet below the 

 layers noticed. 



The same layers, but with some change, are quarried to the west of Palatine bridge ; they 

 are also exposed for many rods by the side of the railroad, opposite to Fort-Plain. Numer- 

 ous fragments of fucoids may there be seen, and it is the only locahty of the Orthoceras pri- 

 migenia. 



Exudations of hydrate of iron are common to many parts of the side-hill at the quarry, con- 

 sisting of tlie ochrey or bog ore, and appearing to have passed either from those layers or the 

 overlying ones of the birdseye. 



The layers extend along the road between Palatine church, and St. Johnsville. They 

 diminish greatly towards the west, being very thin at Little-Falls, and appearing near the 

 top of the mass. One of the places noted in that vicinity, was the old mill to the southwest 

 of the falls. 



These layers were seen at many points in Montgomery county, north of the Mohawk. 

 They appear under the mill-dam at Cranberry Post-office, and are not thick, but straight ; 



