30 Geology, Se. of the Connecticut. 
It may not be amiss to state here that the greenstone of 
the Connecticut has a very different aspect internally and 
externally from the epidotic and sienitic greenstones in the 
vicinity of Boston. ‘The latter are evidently transition, be- 
ing associated with the sienite, porphyry, gray wacke, argil- 
lite, &c. But | am not prepared to state precisely in what 
respects they differ from the greenstone of the Connecticut. 
And although it does not strictly belong to this place, it 
may not be amiss to refer to the interesting dykes of basal- 
tiform greenstone occurring in sienitic granite in the vicini- 
ty of Boston, of which I do not recollect to have seen an 
account. Ihave noticed them in Sudbury and Weymouth 
in real granite—that is, the rock was destitute, at the place 
of hornblende. One in Weymouth, or perhaps in Brain- 
tree, I traced several rods, and it retained its width with 
mathematical exactness, and the sides were perfectly 
smooth. These dykes deserve more examination and bet- 
ter description. Perhaps some of them contain real basalt. 
White Augite. 
‘Since writing the account of this mineral found in Go- 
shen, which occurs on page 225 vol. 6. I have visited the 
locality again, and find it in immense abundance. About 
two miles north of Goshen meeting house, a few rods be- 
yond a tavern on the west side of the road, is a pasture al- 
most covered by bowlders of granite. These bowlders are 
full of augite, some of the crystals of which are from twelve 
to eighteen inches long and three or four wide, although 
they are very imperfect. Every cabinet in the world might 
be supplied from them. I noticed also in the same rock 
some crystals of beryl more than an inch in diameter. 
Bree! Precious Garnet. 
This occurs abundantly in gneiss in west and south 
Brookfield. Some are an inch diameter; their colour is 
light poppy red, and it is rare to find any exhibiting the 
form of the crystal distinctly, so that perhaps they ought 
to be referred to pyrope. 
aS Peek Prismatic Mica 
‘Found in the northern part of Williamsburg in granite. 
Good specimens may thence be obtained. 3 
