374 Dr. Hunt on the Primordial Zone 



ARTICLE XXYTII. — Mr. Barrande on the Primordial Zone in 

 North America^ and on the Taconic Systenfi of Emmons. 

 By T. Sterry Hunt, M.A., F.R.S. 



We are indebted to the courtesy of tbe author for a copy 

 of his paper on this subject, extracted from the l8th volume 

 of the Bulletin of the Geological Society of France, and 

 including three communications made to that Society, November 

 5 and November 19, 1860, and February 4, 1861. The commu- 

 nications of Sir W. E. Logan, and of Mr. Billings, which have 

 appeared in the Naturalist, have already made our readers ac- 

 quainted with the most important facts bearing on the ques- 

 tion before us, and we may also refer to our paper on Ameri- 

 can Geology in the April number, written before the reception of 

 Mr. Barrande's memoir. This the author has divided into eight 

 chapters, in the first four of which he discusses the evidences of a 

 primordial fauna in Canada, Vermont, Tennessee, Texas and 

 Nebraska. Our readers are already aware that in 1859, Mr. Hall 

 described three species of Olenus from Georgia, Vermont, besides 

 which the observations of Roemer, Shumard, and SaflPord, have 

 shown the existence of related genera, in Tennessee, Nebraska 

 and Texas, where they occur in strata which are recognized by 

 these authors as being at the base of the palaeozoic series. The 

 observations of Mr. Barrande upon the remarkable fauna from 

 Point Levis, are so important that we translate them at 

 length, referring to Mr. Billings's description of the four groups of 

 fossils, which will be found in the Naturalist for August 1860, 

 Vol. v., p. 301. 



" The group No. 1 is distinguished from all the others by several 

 very remarkable characteristics. Of the eight genera of fossils, two 

 are brachiopods and six trilobites, so that the latter furnish three- 

 fourths of the types of the group. If we compare the species, the 

 brachiopods are three and the trilobites eighteen in number, or 

 six-sevenths of the known species of the group. These numerical 

 relations, indicating a great predominance of trilobites, recall in a 

 striking manner one of the principal characters of the primordial 

 fauna. 



" Among the trilobitic types are four forms which up to 

 the present time, have been found to belong exclusively to the 

 primordial fauna; namely, Concephalites^Arionellus^Menocephalus 

 and Dikellocephalus; besides which the genus Agnostus furnishes 



