1867.] 347 [Perry. 



species of Chondrites, Palceophycus inclpiens (B.), and P. congrer/atus 

 (B.), Obolella cingulata (B.), an undescribed species of OrtJiis, Orthisma 

 festinata (B.), Camerella antiquata (B.), OleneUus Thompsoni (H-), O. 

 Vermontana (IL), and Co)iocepJiaIites Teucer (B.) , with one or twootbei' 

 S2)ecies of trilobites, probably as yet undescribed.* On tlie other hand, 

 I have collected in the Potsdam Sandstone several species of described 

 and undescribed Fucoids (PakcopJiycug), Scolithus linearis (H.), one 

 or two species of Lingula, the remains of several other Bracldopods as 

 yet undescribed, fragments of Crinoidcd stems, also Conoceplmlites 

 Adamsi (B.), and C. Vulcanus (B.). To these might be added two 

 or three other species, hitherto discovered in these Vermont beds, 

 and already described, with which I have thus far failed to meet. 

 Now it is observable, and worthy of remark, that the several fossils 

 just enumerated, as occurring in these two main groups — in short, 

 that all the organic remains thus far brought to light in these strata — 

 are specifically distinct. It is, in fact, possible, if I mistake not, to 

 go even further and say, that no species is yet known to have been 

 discovered, either in Vermont or elsewhere, common to the two sys- 

 tems of rocks; that thus, so far as we are aware, the lower series and 

 the higher are resjDectively characterized by distinctive fossils, each by 

 those peculiar to itself;f and, therefore, that Ave fail to find any evi- 



.*The latter crustaceans I discovered, not long ajjo, in a mass of slaty lime.stoue, 

 apiiarcutly imbedded in Georgia SIsite; both the liniestoue and the slate are fossil 

 ferous ; but I have, up to the present, failed to find time, either to examine the mass 

 as I desire, or to study the few specimens which I collected. 



t As an aid to the eye, and since there will be occasion to refer to these organic 

 remains again, it may bo well to present them in a tabular form. Omitting the 

 Lower Taconic, and reading from below upward, we have : 

 f Conocephalites Vulcanus (B.). 

 j " Adamsi (B.). 



I Several species of Bi-achiopods undescribed. 

 II. Potsdam Sandstone, -j Lingula, probably two species. 

 I Scolithus linearis (H.). 

 I Crinoids. 



l Fucoids, described and undescribed. 

 Articulates, undescribed, probably two species. 

 Conocephalites Teucer (B.). 

 Olenellus Vermontana (H.). 



Thompsoni (H.). 

 Camerella antiquata (B.). 

 f Georgia Slate. H Orthisina festinata (B.). 



Orthis, undescribed. 

 Obolella cingulata (B.). 

 J i Palseophycus congregatus (B.). 



" inclpiens (B.). 



Chondrites, one or two species undescribed. 

 One or two undescribed sjjecies of Articulates. 

 Atops trilineatus (Em.). 

 , Graptolithus, several species. 



Swauton Slate. 



