378 J. D. Dana—Hudson River Age of the Taconic Schists. 
similar to the limestone region east of the Taconic Mountains 
in having large limonite beds, not only in Copake and farther 
north, but also in Central Ancram and beyond to the south ; 
among them the Reynold’s ore-pit, three to four miles south- 
west of the Weed ore-pit of Southern Copake, and the Morgan, 
a mile and a half farther south. Thus the observations accord 
well with the view that the limestone belt which borders 
conformably the Hudson River argillaceous schist of Pough- 
stone formation that outcrops around Dorset, Rutland and 
Middlebury, Vermont. The occurrence of limonite beds along 
the junction between the schists and limestone, as a result of 
their alteration, in both the eastern and western belts, is an 
additional mark of general identity. 
Copake limestone belt, west of the area of the Taconic Moun- 
tains. The map also gives the position of the southern part 
of the “Great Central” limestone belt of the Green Moun-— 
eight miles south of Pawling, and just east and f the 
Archean Highlan These areas, where broadest, include some 
intercalated beds of schist and isolated schist e map also 
ig : 
that of Kent and Cornwall, and that of Brookfield and New 
Milford. The T-like symbols over the map, indicate the strike and 
dip from my observations. | 
(8.) Besides this stratigraphical evidence we now have more 
positive evidence from the occurrence of Trenton fossils in the lime- 
stone of some parts of Wappinger Valley. 
Professor Mather makes the statement in his quarto New York 
ne (repeating it from his Annual Report of 1838), that in a 
of slaty limestone existing in the slates one-and-a-fourt 
to one-and-a-half miles north of Barnegat, “a few fossils were 
