174 BULLETIN OF THE 
similar in character and arrangement to the same minerals outside that we 
have to suppose they were all formed together where we now find them. 
This is the well known character of these pseudo-porphyritic feldspars 
in phyllite-gneiss or feldspar-phyllite in general, and in the present case 
their character as albite has been proved by chemical and optical analy- 
sis. That they should have some connection with the grains of true 
detrital feldspar found in the less metamorphosed phyllites of this region 
is easy to see, but difficult te prove. 
It should be mentioned that the Hoosac conglomerate in its fine 
schistose portions contains little glassy feldspars with albitic characters. 
This conglomerate occurs at intervals for more than a hundred 
miles to the north, well into the centre of Vermont, lying between the 
Cambrian quartzite of the Taconic region and the underlying gneisses 
on the east. 
One of the most striking localities is on Bear Mountain in Walling- 
ford, a few miles southeast of Rutland, Vermont, which was described 
and figured in the ‘“ Geology of Vermont,” Volume I. pages 32 and 34. 
The conglomerate character is exhibited in wonderful perfection, the 
pebbles varying from almost boulder size to that of the grains of the 
finest sandstone. They are principally quartz (often blue) and feld- 
spar; the latter are generally of a dull white or reddish color, due 
to kaolinization. One of the large feldspars, tested by the ordinary 
methods, proved to be microcline. In the Hoosac conglomerate this 
feldspar also occurs in the pebbles and in the underlying coarse gneiss 
from which they were derived. In the finer grained layers of the Bear 
Mountain rock the cement predominates, so that the rock is a crystal- 
line schist containing little pea-sized angular grains of quartz and feld- 
spar. This cement rock here and at other localities glitters with small 
glassy feldspars, as does the albite schist of Hoosac Tunnel. 
In the finer grained portions of this conglomerate schist the detrital 
feldspars show interesting changes, which may throw some light on the 
formation of albite schists. The descriptions which follow are based on 
material from one hand specimen, so that it will be understood that the 
changes observed are progressive only by comparison, feldspars side by 
side having been affected to a varying degree by the forces of metamor- 
phism, obliterating partially or else completely the original characters. 
In the hand specimen the rock is a silvery green schist, the color 
due to large scales of a light green muscovite, which are arranged in 
parallel layers, and enclose between the meshes little elongated masses 
of quartz, and little glassy feldspars, which are barely visible with the 
