1867.] 349 [Perry. 



the underlying slates may after all be Utica, tlie Potsdam beds liavino 

 been jiiislied westward, and thus made to overlap them in their great- 

 est extension to the east. That, perhaps, the sandstone was moved 

 laterally, at an early day, — that there are, in places, what are called 

 slickensides, — that there may be occasional masses of the Utica 

 along the western mai-gin of the Potsdam, — no one, though he closely 

 question the points, need altogether to deny; for these, in j^art at 

 least, are facts: but, at the same time, there is abundant evidence 

 that the lateral movement of the sandstone over the slate was not 

 extensive; indeed, there is incontestible proof, which cannot be here 

 given, that in many instances it could not have exceeded a few inches 

 at the most; that thus it was by no means eqtial to almost the entire 

 width of the formation; that, therefore, it was wholly insufficient to 

 make the easterly limits of the two systems of rocks, in different 

 places, nearly conterminous. 



Wliile, then, these subjacent beds cannot be properly regarded as 

 Utica Slate or Lorraine Shale, because of their stratigraphical posi- 

 tion beneath the Ked Sandstone; while their nonconformity with it 

 also indicates, beyond all controversy, that they are different from 

 and older than the Potsdam formation, — we should still remember 

 that their included organic remains have important testimony to 

 bear — testimony to which I have as yet made no direct reference. 

 It is to this effect: these organisms show that the underlying slates 

 clearly answer to the Primordial Zone of Barrande. In a word, the 

 fossils found in these lower rocks — in the Swanton and Georgia 

 Slates — of the counties of Addison, Chittenden and Franklin, and 

 already referred to, are, as I presume no one now denies, unmistak- 

 ably of a primordial type. 



So is it, as we may see when we look at the matter broadly, with 

 the fossils of the overlying Red Sandstone. They most certainly be- 

 long — not in a narrow, not again in the widest, but in a wide view of 

 the subject — to what is called the Primordial Zone of Life. By this 

 is meant — not that they are the remains of the very first li^ino- 

 creatures that appeared on the globe (for the Potsdam, as we have 

 seen, is not the oldest fossilifcrous formation) ; not merely, on the 

 other hand, that they are found in the great Palaeozoic circle of rocks, 

 but — that they are a part of the first grand type of life, so far as we 

 are yet able to determine it. They are, however, later — a trifle later 

 in the geologic sense of the term — than the organic remains of the 

 subjacent beds of slate. They are later, I say, and yet, as I grant 

 with equal readiness, they are closely allied..- But in freely admitting 

 that they are nearly related in organization, I would not neglect 

 emphatically to add, that they are by no means identical. While 

 they are in some cases generically the same, they are always, so far 



