Luthological Conclusions. 259 
vite, and also small green grains of epidote; (15) syenyte gneiss, 
consisting mainly of hornblende and whitish feldspar, not 
common ; (16) hornblende slate, occasional beds; (17) pyroxenyte, 
consisting of white pyroxene (at Canaan, Conn.). 
arnet rock, a firm tough rock of a blackish-gray color, 
consisting of quartz, pale-red garnet, some feldspar, magnetite 
an rite, and also minute disseminated prisms showing one 
lustrous cleavage which may be zoisite (from Beartown Moun- 
tain)— 
eral successive beds of the former, or taking wholly its place in 
the formation. 
3. Schists along an East-and- West section of the limestone region. 
In Vermont.—The schists of a,section across the limestone 
region from west to east in the line of Rutland, are the same 
nearly as occur in the Quartzyte group from north to south, 
argillyte being the only rock to the west not found to the east. 
In wre.—The remark just made for Vermont applies 
equally to Berkshire. Along an east-and-west section i 
southern Berkshire, there are, commencing to the west: argil- 
lyte, various kinds of hydromica slate, from a black glossy 
slate differing little from argillyte, to pale pearly slates, chlo- 
ritie and garnetiferous hydro-mica slates; farther east, fine- 
grained mica schist and gneiss, coarser garnetiferous mica 
schist and staurolitic mica schist; and all the gneisses and 
other rocks mentioned above. 
Thus the same kinds of rocks are met with on going from 
east to west across Berkshire as in going from north to south 
along the Quartzyte ranges of Vermont and Berkshire. 
The above lists afford an idea of the great diversity in the 
crystalline rocks of the limestone series We are now pre- 
ed for a conclusion. 
Since then these rocks of the limestone series are confoi 
able, and of Lower Silurian age; and since they were all 
crystallized into their present state after the Lower Silurian 
