230 



frequently reddisli tint, Avould lead us to regard tliein as a contin- 

 uation of the lower mass under somewhat new formative con- 

 ditions. In the prolongation of this belt of sandstones and lime- 

 stones toward the north, as at AVinooski Falls, near Burlington, 

 the latter mass is seen to consist in great part of a pinkish white 

 fine-grained limestone, which toward the base contains layers of 

 reddish limestone interstratified with red sandstone, — marking the 

 transition from the arenaceous to the calcareous form of deposit." 



" In none of the localities of this calcareous mass which I have 

 examined, from the flank of the Snake Mountain to near the Can- 

 ada line, have I found any well-marked organic remains. This 

 fact of itself strongly favors the idea of its being but a peculiar 

 development of the upper portion of the Medina group. Nor can 

 it be objected to this that metamorphic action may have caused 

 its present destitution of fossils. Throughout nearly the whole of 

 the series of exposures extending due north toward the Canada 

 line, it presents a gentle eastern dip, conforming to the subjacent 

 fossiliferous beds of Matinal limestone and slate, from which it is 

 separated only by the sandstones above described. From this we 

 infer that it must have been as little exposed as these fossiliferous 

 beds to agencies capable of obliterating its included fossils, and 

 that therefore it has never been in any considerable degree a fos- 

 siliferous mass." 



" We are further strengthened in the opinion that this calca- 

 reous group, with the subjacent sandstone, belongs to the Medina 

 period, by the consideration that the Clinton group, with which it 

 might otherwise be compared, is almost everywhere an eminently 

 fossiliferous one. From Alabama to northern New York, it is 

 marked by an abundance of fossils. According to Mr. Logan, 

 strata of this age are found in the vicinity of Lake Memphrema- 

 gog, and, although there surrounded by metamorphic masses, they 

 include a number of fossils in good preservation." 



" On the whole, therefore, I think that the limestone and sub- 

 jacent sandstone of which we are noAV treating must be regarded 

 as one formation, and may with the highest probability be refer- 

 red to the period of the Levant rocks or the Medina group of 

 New York." 



Dr. White exhibited a section of the tusk of an ele- 



