HUDSON RIVER GROUP. 
63 
To the west, at the lower mill below Vanhornsville, and also at Yawheiur creek to the 
east of Mr. Shawl’s, the water falls over the conglomerate and the slate, into the deep gulfs 
excavated in the slate by the waters of the creeks. At the mill, nulnerous graptolites, the 
G. * * * *, exist in the slate at the top of the mass, which was uncovered in making its 
foundation. Thin layers of sandstone in alternation with the slate, being a common - character 
of the mass, appear in the gulf; towards the bottom of which, near the depth of one hundred 
feet, it is more coarse, and there assumes the character of the thick layers in Schoharie. 
The points further west, where the slate also passes under the overlying rocks, enume¬ 
rating them in their geographical order, are -first, by the side of Wicks’ store, in the brook, 
which exhibits but a small excavation in the slate ; in Fulmer valley, it shows itself in many 
points, the greater part of the valley consisting of the slate ; in Steel’s creek and Myers’ creek 
back of Frankfort, whence the name given in the second year of the survey. The latter creek 
affords the best opportunity for observing the edges of the slate, which extend like a wall for 
two miles up the creek. It shows' thin layers of sandstone, at variable distances from each 
other, separated by slate. A good point also is at Starch-factory creek, and another at the 
hill which projects north between the creek and Utica ; and a still better one presents itself in 
the long and deep^gulf to the south of the Minden turnpike, the entrance to which faces the 
southeast end of the city. Its whole length and depth is excavated in-the slate, which disap¬ 
pears under the Oneida conglomerate, over which the water falls at the head of the gulf. 
The mass in the gulf consists of slate, and sandstone slate, none but very thin layers being 
observed. Towards the. upper part of the slate, the Cryptolithus and the Triarthus were 
found, the latter not more than one-third of the.usiial size ; and also two or three thin bi¬ 
valves, quite small, not yet described, figured or named. These fossils appeared to be rare ; 
and from their small size, could readily have been passed unnoticed. Only one specimen 
of the Triarthus was found, and but two of the Cryptolithus. 
The last place to the south of the Mohawk, where the Frankfort slate appears in the hill¬ 
side, is under the conglomerate on the farm of Mr, Mason, on the hill to the east of New- 
Hartford Centre. 
North of the Mohawk, it covers the high hill which extends through the towns of Schuyler 
and Deerfield, surrounded by Utica slate in all directions. The range which turns north from 
the Mohawk, shows itself at Ridge’s mill to the north of Rome, and in some of fhe small 
streams which flow east into the Mohawk and its east branch, Lansing-kill. Through Oneida 
and Lewis counties, its range is undisturbed; it presents no change of character, and appears 
in all the water-courses of the latter county which flow east, over the limestone, to the river. 
The Frankfort slate and sandstone, though so thick a mass, and placed between two such 
highly fossiliferous rocks as the Trenton limestone and the sandstone shale of Pulaski, is 
remarkably deficient in organic remains, excepting in graptolites. In the third district they 
are, however, but few in number when compared with the first district; there they exist in 
great number, in excellent preservation, showing from four to five species, and are found in 
many localities. The illustration of this rock by its graptolites is therefore left for the geolo¬ 
gist of that district. We shall merely state that the ramose nature of two of the species of 
