J. D. Dana—Taconic Rocks and Stratigraphy. 207 
A few localities of glacial markings are recorded by means 
of a symbol consisting of three parallel lines, with a dot on the 
middle one marking the locality, and figures at ithe southern 
end indicating the angle with the meridian. 
_ The roads are given because they were often used as a base 
in fixing the limits of rocks and the positions of localities ; and 
also because it was desirable to mark the localities of the strat- 
graphical sections inserted in the text so plainly that any 
questioning geologist could go and see for himself and not 
ag of one another ; but beyond this distance, it is uncertain, 
800 y ards and sometimes, a much shorter interval, through an 
‘tticlinal. In each diagram the east or north end of a sechon 1s 
d. 
n the study of Berkshire County I have been much bene- 
Professor 
Hitchcock, which gives a good general view of the 
I Personal observations.* ; ; 
N n all geological maps, and especially in one of eastern 
orth America, the lines are in some parts unavoidably con- 
* A geologi . inted in the 
J ogical map of the Taconic region accompanied my paper prin 
Ournal of the Geological Society of London for 1882. In preparing it, the Berk- 
and Vermont portions of the map were copied, with very little aes* 
“the alse from my own observations—then too incomplete for satisfac- 
Tenn rales a strong motive prompting me to a more detailed survey of 
on. 
