2. _Gneiss_ and _Mica Slate_. I connect these two, because they are not often distinct, and appear to pass into each other. They are found in large strata on Hoosack Mountain, on a hill (L) connected with Saddle Mountain, and on the east side of Saddle Mountain. The highest and the west ridge of Saddle Mountain are mica slate. The _Hopper_ shows the inclination of the strata quite to the base of the mountain. The inclination is to the east and northeast, from ten to forty degrees. On the southwest mountain of _Saddle_, the strata are bare to the summit for a considerable distance, and are very fine grained mica slate, having somewhat the appearance of a _soapstone slate_. By this name they are called in Mr. Eaton's Index to Geology. Some of the rocks appear to be _talcose_. I have been able, however, to detect but a very minute quantity of magnesia in any specimens I have tried, though I obtained a considerable proportion of alumine. The higher hills of the Taconick range are composed principally of a similar slate, lying in the same direction, and with similar inclination; but it appears to have passed still farther from mica slate. At the northwest corner of the state, which is near the foot of the ridge in this place, the rock is very similar to some of that on the southwest mountain mentioned above. About a mile northwest of this _corner_, the rocks are cleft in several places, and in one, to such a depth, that the snow and ice remain here through the year. The _Snow Hole_ (M) is about thirty feet long, and nearly as deep at the east end, ascends to the west, or towards the summit of the ridge, and is from ten to twenty feet wide. When I visited it in June, the snow was six feet deep on ice of unknown depth. The rock is here passing into _argillaceous slate_; and in many places it becomes _argillaceous_ and _chlorite slate_. For the other rock, you have, I believe, proposed the name _talcose slate_.