GEOLOGY. 343 



described at length in 1844, and named the Taccnic System. The arguments 

 of Prof. Emmons for the existence of this system were based on certain 

 fossils, and on stratigraphical and lithological grounds, which to him appear 

 good and sufficient reasons. His views, however, have been almost univer- 

 sally rejected by American geologists, and of late but little has been said on 

 the subject. Recently, however, the matter has been brought up in the 

 Boston Society of Natural History by M. Marcou, who supports the views 

 of Dr. Emmons, and adduces the testimony of M. Barrande, the well-known 

 European palaeontologist, also in confirmation of them. M. Marcou says 

 the discovery of Paradoxides Harlani at Braintree, Mass., and that of Para- 

 doxides Bennctti and Conocephalites at St. Mary's Bay, Newfoundland, in 

 slates until then regarded as Azoic and placed among the crystalline and 

 primary rocks, show plainly that the Primordial fauna (recognized in 

 Europe as existing before the Silurian epoch) is represented also on the 

 Atlantic coast of North America. These are not isolated facts, but rather 

 two landmarks showing the existence of strata occupying an important 

 place in the system of stratified rocks. 



M. Barrande, in a letter to M. Bronn of Heidelberg, also takes the posi- 

 tion that the remains of certain species of trilobites, found in that part of 

 the Taconic system of Emmons which is referred by other geologists to the 

 Hudson River shales, are so unmistakably decisive in their character, that 

 any European paleontologist familiar with these fossils would, without 

 doubt, refer them to the formations which are recognized as being older and 

 inferior to the Silurian System. " Such is my profound conviction," says 

 M. Barrande, in his letter to M. Bronn, " and I think any one who has 

 made a serious study of the trilobitic forms and of their vertical distribu- 

 tion in the oldest formations will be of the same opinion. Besides, all who 

 have seriously studied palaeontology know well that each geological epoch, 

 or each fauna, has its proper and characteristic forms, which, once extinct, 

 reappear no more. This is one of the great and beautiful results of your 

 immense researches, which have generalized this law, recognized by each 

 one of us within the limits of the strata he describes. The great American 

 palaeontologist arrived long since at the same conclusion, for in 1847 he 

 Avrote the following passage in the introduction to the first volume of the 

 Monumental Work consecrated to the Palaeontology of New York. ' Every 

 step in this research tends to convince us that the succession of strata, when 

 clearly shown, furnishes conclusive proofs of the existence of a regular 

 sequence among the earlier organisms. We are more and more able, as we 

 advance, to observe that the Author of nature, though always working upon 

 the same plan, and producing an infinite variety of forms almost incompre- 

 hensible to us, has never repeated the same forms in successive creations. 

 The various organisms called into existence have performed their parts in 

 the economy of creation, have lived their period, and perished. This we 

 find to be as true among the simple and less conspicuous forms of the Paleo- 

 zoic series, as in the more remarkable fauna of later periods.' J. Hall, 

 Pal, of New York, i. p. xxm. When an eminent man expresses such 

 ideas so eloquently, it is because they rise from his deepest convictions. It 

 must then be conceived that J. Hall, restrained by the artificial combinations 

 of stratigraphy previously, adopted by him, has done violence to his palaeon- 

 tological doctrines, when, seeing before him the most characteristic forms 

 of the Primordial fauna, and giving them names the most significant of 

 this nrst creation, he thinks it his duty to teach us that these three trilobites 



