TABLE OF CONTENTS. XIX 



ublication of Murchison's Silurian System 355 



imculty of distinguishing between Cambrian and Silurian . . . 355 



Sedgwick's views and position misrepresented ...... 357 



Errors of Murchison's sections exposed 358 



His Silurian system based upon a series of mistakes 362 



Sedgwick's proposed compromise in nomenclature .... 363 



Unauthorized alteration of Sedgwick's geological map .... 364 



Further history of Sedgwick's wrongs 364 



PART II. MIDDLE AND LOWER CAMBRIAN. 



Ancient fossiliferous rocks of Scandinavia 365 



The early studies of Hisinger ; curious errors 366 



Section of the rocks of Kinnekulle ........ 367 



Angelin on the Crustacea of Scandinavia 367 



Barrande on the fossiliferous rocks of Bohemia 368 



The so-called primordial Silurian 369 



The fossils of the Lingula flags of Wales 370 



Fossiliferous rocks of the Malvern Hills 370 



Subdivision of the Lingula flags ; the Menevian beds .... 371 



Fossils of Lower Cambrian or Harlech rocks . 372 



True boundary between Cambrian and Silurian ..... 374 



Breaks in the succession of the lower rocks ...... 375 



Note on the Tremadoc rocks 375 



Ramsay on stratigraphical breaks 376 



General considerations on breaks in geological series .... 377 



Note on the thickness of British Cambrian and Silurian . . . 377 



Murchison and the Cambrian nomenclature ...... 378 



He confounds the Longmynd and Bala groups 380 



The statements of his Siluria criticised 380 



Disagreement as to the Cambrian and Silurian nomenclature . . 381 



Distribution of Lower and Middle Cambrian rocks 382 



Crystalline schists of Malvern and of Anglesea 383 



Gold-bearing Lingula flags of North Wales 383 



Hicks on the classification of lower palaeozoic rocks .... 384 



Sedgwick's latest views on classification 384 



Tabular view of lower paleeozoic rocks 386 



PART III. CAMBRIAN AND SILURIAN ROCKS IN NORTH AMERICA. 



The geological survey of New York 387 



Hall on the rocks of the New York system 387 



The Taconic system equivalent to Lower and Middle Cambrian . . 388 



The paleontological determinations of Hall ...... 389 



Stratigraphical errors of the Taconic system ...... 390 



The Red sand-rock and the primordial trilobites of Vermont . . 391 



Contributions of Barrande and Billings to the subject .... 392 



Logan on the Taconic rocks of Vermont 394 



Hall's determinations and the errors of Hisinger 395 



Bigsby on the fossiliferous rocks near Quebec 396 



Bayfield and Logan on the same rocks 397 



