436 J. D. Dana on some points in Lathology. 
an 
a part of the general gneissic formation of the region. (8) The 
labradorite-dioryte two miles west of New Haven graduates 
often and variously, that there is no reason for questioning its 
metamorphic origin. (ce) A hornblende (or actinolite) rock, 
just northeast of Bernardston, of a massive kind, occurs among 
thin schistose beds of mica schist and hornblendic schist and is 
are massive 
wherever hornblende is the chief ingredient. It explains also 
the existence of the massive labradorite-dioryte among tne 
syte, quartz-felsyte, granulyte), is almost sure, under the circum- 
stances mentioned, to make a rock, with the bedding obliter- 
structure that favors any other condition. 
(8.) Pressure may be a source of schistosity or foliation, and it may 
also obliterate bedding. On the first of these points illustration 
is not necessary. As to the second, there are many examples 10 
the crystalline limestone region of Western New ae , both 
in Vermont, Massachusetts and Connecticut. At West Rutland, 
Vermont, as first observed by Prof. Edward Hitchcock, many 
limestone beds have been cemented by the pressure which gave 
them their high dip into a bed of great thickness, so that masses 
as large as a moderate-sized house could be cut out if needed. 
complete enongh to obliterate the fossils—shells, corals and 
— 
crinoids being distinguishable; so that there could have been 
