356 



ORGANIC REMAINS. 



Iron pyrites are considerably common in small bright crystals. In the east part of Middlebury, high 

 upon the Green Mountains, upon the land of Allen Foote, some strata have been discovered containing an 

 unusually large proportion of crystals of magnetite sufficiently numerous to be of considerable value in 

 the vicinity of iron furnaces. 



A small amount of plumbago is found in Chittenden and Brandon. Galena and copper pyrites are also 

 ascribed to Brandon, and Prof. Thompson speaks of iolite in Chittenden. 

 Veins in Quartz rock. 



Sometimes this rock contains veins of quartz scarcely separate from the base. They are usually white 

 . 253. an( i opaque, and the rock a mixture of gray quartz and mica 



the latter mineral existing, however, in very small proportion. 

 Fig. 253 is a sketch of a bowlder about eight inches in diameter, 

 which was originally from western Vermont, although it was 

 picked up in Amherst, Mass. The principal part of it is gray 

 quartz traversed by numerous veins of white quartz. 



Organic Remains in the Quartz Rock. 



Several species of fossils occur in the quartz rock. They are 

 a species of Lingula, a mollusk resembling the Modiolopsis, a 

 straight chambered shell (?), a few crinoidal columns, the 

 Scolithus linearis (Hall), a few fucoids, and some indetermin- 

 able forms which are evidently organic. 

 Veins in Quartz rock. The Lingula is from the north part of the princ ip a l range of 



quartz rock in Starksboro, near Kockville, at the house of Mr. Hill. The locality was discovered by Henry 

 Miles, of Monkton. The specimens contain scores of fossils, but none of them are very distinct. Prof. 

 James Hall has examined them, and regards them as a new species of Lingula, related to a species contained 

 in the Medina sandstone. 



The " Modiolopsis," chambered shell, and encrinal remains are found in hyaline quartz on the west side 

 of Lake Dunmore. The first and last were referred to the same authority by Prof. Adams. The following 

 remarks concerning them we quote from Foster and Whitney's Report upon the Land District of Lake 

 Superior, 1851, Part II, p. 205. "I have recently received from Prof. Adams, of Amherst, specimens of 

 partially metamorphosed sandstone from Salisbury, Vermont, which he regards as the equivalent of the 

 Potsdam sandstone. The specimens have all the characters of the purely quartzose variety of this rock, and 

 contain fragments of crinoidal columns, and casts of an acephalous bivalve, similar to Modiolopsis. 



" Such facts are highly interesting, and promise important results for the future. Since, however, no 

 known fossils of the Potsdam sandstone occur with the rocks just mentioned, it requires a careful scrutiny to 

 determine the age of the rock in situ." 



The Scolithus linearis (Hall) is regarded by some as a plant, by others as a relic of an articulate animal. 

 It generally presents the appearance of numerous linear stems, sometimes three feet long. The stems are 

 generally numerous, and much resemble a series of small pins driven into the 

 rock. Some authors have stated that the axis of this fossil is invariably at right 

 angles with the position of the strata. If so, it may be of great service where 

 it occurs in settling the position of the strata. It certainly would be in both of 

 its localities in Vermont. The generic character of Scolithus is that of a 

 stem, free, simple, cylindric or subcylindric, vermiform or linear, and never 

 branched. The 8. linearis has a simple rectilinear stem ; its surface is nearly 

 even, cylindric or compressed, and is sometimes apparently striated. Fig. 254 

 represents the Scolithus linearis from Vermont. 



In the north part of Bennington, in Gen. Harwood's Quarry, there is a very 

 fine locality of this species. The specimens are remarkably abundant and 

 beautiful (Nos. B ? i , B% in the Cabinet.) Where the rock has been altered or decomposed into glass sand, the 



Fio. 254. 



Scolithua linearis. 



