No. 275.1 
195 
discovered it, and removed it to my cabinet, and considered it as bear- 
ing such strong evidence of its source, that 1 shall forward it to be pre- 
served in the State cabinet at Albany. 
9. Ferruginous Sandstone or Jasper rock, like that found in place un- 
derlying the Palissades, near Fort Lee, 
This rock which is one of the most abundant next to greenstone and 
granite, in the south part of the island, I have not found north of the 
Harlem and Manhattan ville valley. It is most abundant between 13th 
and 20th-streets, and between 2d and 4th avenues. This rock, when 
first noticed, was supposed to be a ferruginous quartz in a state of dis- 
integration; but on a closer inspection, an obscure appearance of strati- 
fication was observed, and the component grains were found rounded 
and often transparent, and cemented together by a large amount of ox- 
ide of iron. In some specimens it is difficult to identify the granular 
structure on account of the abundance of the cement, and the advanced 
stage of decomposition in which it is found; in others, there is so inti- 
mate a union between the parts, that the whole seems to be one entire 
mass. There are others, again, where the cement puts on the appear- 
ance of jasper, and hence the name of jasper rock, which has frequently 
been applied to it. 
In searching for the geological place of this rock, I am satisfied I 
have found it underlying the Palissades in the neighborhood of Fort 
Lee, where the red sandstone comes out under the Palissades very near 
the water's edge, and exhibits a great variety of character. Specimens 
of this rock are forwarded. 
10. Clay stone, supposed from the same formation as the last; they 
are distinctly stratified, and have a clay colour. They are often quite 
hard and slaty in structure. Specimens of this rock are forwarded. 
11. Adynolite, supposed from the anthophyllite locality. This va- 
riety has been found in boulders at Corlear's hook, and in other places 
in the southern part of the island. One of 3 or 4 feet in diameter was 
discovered in 1826, near the corner of Monroe and Montgomery- streets, 
I preserved a single specimen, and remember distinctly the character of 
the whole mass; and on comparing the specimen in my possession with 
the varieties of anthophyllite in place, I doubt not that all the speci- 
mens of actynolite on the island have been transported from this source. 
12. Kyanite, All the specimens of this rock tl^at have come to my 
knowledge were in loose fragments lying on the surface, inferior in qua- 
