PRIMORDIAL FAUNAE. 385 



In the present discussion, it appears to me necessary to go further, and to inquire in what manner we 

 have obtained our present ideas of a primordial, or of any successive faunae. I hold that in the study of 

 the fossils themselves there were no means of such determination prior to the knowledge of the stratigraph- 

 ical relations of the rocks in which the remains are inclosed. There can be no scientific or systematic 

 palaeontology without a stratigraphical basis. Wisely then, and independently of theories, or of observa- 

 tions and conclusions elsewhere, geologists in this country had gone on with their investigations of 

 structural geology. The grand system of the Professors W. B." and H. D. Rogers had been wrought out 

 not only for Pennsylvania and Virginia, but for the whole Apalachian chain; and the results were 

 shown in numerous carefully worked sections. In 1843, '44 and '45, I had myself several times crossed 

 from the Hudson River to the Green Mountains, and found little of importance to conflict with the views 

 expressed by the Professors Rogers in regard to the chain further south, except in reference to the sand- 

 stone of Burlington, and one or two other points, which I then regarded as of minor importance. 



Sir William Logan had been working in the investigations of the geology of Canada; and better work 

 in physical geology has never been done in any country. 



This then was the condition of American Geology, and investigators concurred, with little exception, in 

 the sequence based on physical investigations. As I have before said, our earliest determinations of the 

 successive faunas depend upon the previous stratigraphical determinations. This I think is acknowledged 

 by M. Barrande himself, when he presents to us, as a preliminary work, a section across the center of 

 Bohemia. With all willingness to accept M. Barrande's determination, fortified and sustained as it is by 

 the exhibition of his magnificent work upon the trilobites of this strata, we had not yet the means of 

 parallelizing our own formations with those of Bohemia by the fauna there known. The nearest approach 

 to the type of primordial trilobites was found in those of the Potsdam sandstone of the northwest, 

 described by Dr. D. D. Owen ; but none of these had been genetically identified with Bohemian forms; * 

 and the prevailing opinion, sanctioned as I have understood by M. Barrande, was that the primordial fauna 

 had not been discovered in this country, until the rediscovery of the Paradoxides Harlani, at Braintree, 

 Mass. The fragmentary fossils published in Vol. I, Palaeontology of New York, and similar forms of the 

 so-called Taconic system, were justly regarded as insufficient to warrant any conclusions. It then became 

 a question for palaeontologists to decide, whether determinations founded on a physical section, in a 

 disturbed and difficult region of comparatively small extent, were to be regarded as paramount to 

 determinations founded on examinations, like those of the Professors Rogers, extending over a distance in 

 the line of strike of five or six hundred miles; and those of Sir William Logan over nearly as great an 

 extent from Vermont to Gaspe. 



It is not possible for me, at this moment, to give the time necessary for a full discussion of this 

 important subject. In presenting these few facts in this form, I am far from doing it in the spirit of 

 cavilling, or as an expression of distrust in any direction. It is plain that the case is not met in M. 

 Barrande's plan of successive trilobitic faunae; and the facts yet brought out do not serve to clear up 

 the difficulty. It is evident that there is an important and perplexing question to be determined, one 

 that demands all the wisdom and sagacity of the most earnest inquirers, and one which calls for the 

 application of all our knowledge in stratigraphical geology and in palaeontology ; one in which coopera- 

 tion, good will and forbearance are required from every one, to harmonize the conflicting facts as they are 

 now presented. The occurrence of so many types of the second fauna in the rocks at Point Levi, 

 associated with a smaller number of established primordial types, offers us the alternative of regarding 

 these strata as of the second stage, with the reappearance of primordial types in that era, or of bringing 

 into the primordial zone several genera heretofore regarded as beginning their existence in the second stage : 

 in either case, so far as now appears, conflicting with the scheme of M. Barrande in reference to the 

 successive faunae of trilobites as established in Bohemia and the rest of Europe. 



For myself I can say, that no previously expressed opinion, nor any "artificial combinations of 



*The glabellae of small Irilohites nndistinguiahable from Conocpphalns occur in tlie Potsdam sandstone near Trempaleau, Wisconsin, 

 on the Mississippi River. 



