4 C. Lapworth — Classification of the Loiver Palceozoic Rocks. 



The necessity for a tripartite grouping of the Lower Palaeozoic 

 Bocks and Fossils, in partial accordance with this fact, has been 

 very generally acknowledged for the last thirty years. The keen- 

 eyed and philosophic Barrande was the first to recognize this truth, 

 and his addition of the " Primordial " to the First and Second Faunas 

 of Mnrchison's original Silurian marked a geologic era equal in 

 importance to the establishment of a new system. How keenly its 

 enthusiastic discoverer watched over, and how zealously he pro- 

 moted and encouraged, the gradual detection and elimination of his 

 "Primordial''' Fauna in Europe and America, are matters familiar 

 and delightful to all earnest students of the history of discovery 

 among the Lower Palaeozoic Bocks. How the facts obtained by 

 Phillips, Salter, and Hicks in Britain, forced even Murchison himself 

 to adopt Barrande's views, and in his later years to become their 

 keenest and most unsparing advocate, is equally well known. The 

 subsequent development of the " Primordial " Fauna in Britain by 

 Hicks, Salter, Belt, and others ; in Sweden by Angelin, Nathorst 

 Linnarsson, and Sjogren; and in America by Billings, Emmons, Hall, 

 and Hartt, has progressed with marvellous rapidity. Every system- 

 atic geologist worthy of the name has, in his turn, been compelled 

 to acknowledge the distinctness and first-rate importance of the 

 " Primordial " Fauna. 



Under one form or another, also, the difference in the facies of 

 the more recent First and Second Faunas of Murchison has been 

 universally admitted from the first, and the rock-groups formed by 

 their including strata have been separated — at least as distinct sub- 

 systems — in all parts of the world. It is indeed true that there have 

 been, perhaps, as many diverse views held with respect to the 

 proper position of the line of demarcation between them, as there 

 have been separate areas of investigation ; and it is only of late that 

 geologists have reached something like a concensus of opinion in draw- 

 ing it with Hicks at the base of the Lower Llandovery. Nevertheless, 

 no honest investigator, either British or foreign, has ever dreamt of 

 disputing the grand fact of the distinctness of these two faunas and 

 the consequent need for the separation of their containing rock- 

 groups in any natural and workable plan of classification. 



Thus, it is hardly possible that any geologist, who is familiar with 

 the rocks and fossils of the Lower Palaeozoics, or who is even fairly 

 versed in the literature of the subject, would at present venture to 

 deny the proposition that between the base of the known fossiliferous 

 series and that of the Old Bed Sandstone there lie three successive 

 rock-groups — each of which is characterized by a special fauna of 

 first-rate geologic importance. 



Further insistence upon this point is probably needless. But if 

 the fact be once admitted, it follows of necessity that the interests of 

 science demand that these three successive rock-systems shall be dis- 

 tinguished by three separate and unmistakable titles. 



At this stage, however, we plunge into the very midst of the 

 conflict of the schools. Friends, foes, and spectators, seem all fairly 

 agreed as to the advisability of a triple division of the sediments. 



