272 J.D. Dana— Taconic Rocks and Stratigraphy. 
stretches on uninterruptedly to Weybridge, beyond Middle- 
bury, making within the hmits of Vermont. another 95 miles. 
The western limestone, or that west of the main Taconic 
Range, is, in. the first place, not a continuous belt; and, sec- 
ondly, two of its long pieces west of Massachusetts are nothing 
but branches from the eastern limestone, being directly con- 
tinuous with it, instead of distinct lines. It ineludes in the 
region here considered, three parts, a northern, a middle and a 
southern, all in eastern New York. The northern is confined 
to the towns of Hoosic and Petersburgh. The middle com- 
mences five miles south of the northern, in northern Berlin, and 
extends about 25 miles through Stephentown and New Leba- 
non to the southern part of the town of Canaan, N. Y. The 
southern has its north end in Hillsdale, N. Y., 8 to 9 miles south 
of Canaan; and thence it continues southward through Copake 
into Ancram (11. to 12 miles), where it divides into two 
branches, each of which, except for a break of 4 to 5 miles, 
extends southwestward to the Hudson, reaching it near Pough- 
keepsie and Fishkill—a distance in all of 50 to 60 miles. Thus 
there is no one independent western belt. 
The two pieces that are only branches from the great Ver- 
mont eastern limestone are (1) the northern and (2) the middle; 
and (3) the southern makes a very near approach to a junction 
with the Massachusetts eastern limestone. 
In further explanation I state that the northern area, or that 
of Petersburg and Hoosic, passes bodily from Hoosiec into 
northern Bennington where it joins the Vermont eastern belt, 
or becomes identified with it. ‘This same northern portion 
nearly makes another junction with the eastern belt, along the 
Hoosic valley in northern Pownal; but about two-thirds of a 
mile of slate intervene. 
The middle one of the western areas, or that which extends 
from Berlin southward to Canaan, stretches northeastward 
from Stephentown through Hancock, Mass., to Williamstown ; 
or, viewed from the other direction, the Williamstown lime- 
stone, which is a southern part of the Vermont eastern (or 
Kolian) limestone, continues on southwestward (as Hitchcock 
first showed) through Hancock to Stephentown and Canaan ; 
so that this western limestone is the southern termination of 
the eastern. The distance from northern Williamstown to its 
extremity in Canaan is about 35 miles, and hence the Ver- 
mont eastern belt, or Kolian, with this its continuation, is 180 
miles long. 
The approach to a junction between the middle western and 
the Massachusetts eastern limestone takes place at the southern 
end in Canaan, where a long tongue runs out eastward in the 
open valley which there crosses the Taconic Range and makes 
