far as Vermont. Dr. Mitchell further observes, 

 that the granitic region terminates abruptly on 

 the bank of the Hudson, at Polliples Island, oppo- 

 site a large rock in Fishkill, twenty miles below 

 Poughkeepsie ; and that forty rods farther on com- 

 mences a schistous region, the schist coming out of 

 the ground on the bank of the river, as if it there 

 formed a bed to the granite. This schist, he adds, 

 serves likewise as a bed to the calcareous strata , 

 scattered throughout the country ; and mentions a 

 block of this kind a mile from Claverack, and four 

 miles from the city of Hudson on the river of the 

 same name, presenting a prominent mass eight hun- 

 dred acres in superficies, filled v/ith shells, none 

 resembling which are to be found in the nearest sea, 

 distant a hundred and forty miles I 



Dr. Mitchell mentions several calcareous ledges 

 near New York, at the place where the streams 

 separate, some running into the Hudson, others into 

 the Sound, or that arm of the sea that faces Long 

 Island. He imagines, that at a period unknown in 

 history the ocean covered this ground, and his opinion 

 is supported by all the facts he mentions respecting 

 the Kaats Kill Mountains. 



These mountains he has found to consist of the 

 same sandstone as Blue Ridge, of which he deems 

 them a continuation. He first imagined these moun- 

 tains to be of primitive formation, because the gra- 

 nites and sandstones contained no fossils ; but he soon 

 found contrary indications : as, 1st, the aspect of rocks 

 containing pebbles or small stones of red and white 

 quartz, sandstone, and red jasper, all evidently rolled 

 and worn by the waters: 2dly, horizontal and very 



