Marcou.] 350 [March 2, 



world. The Transition rocks are divided into systems, as well sep- 

 arated, and as well characterized as the Secondary or Tertiary 

 rocks. The existence of well defined systems among the strata 

 containing the beginning of life on onr planet is no more to be 

 doubted or discussed ; and the Palaeozoic series or era is now di- 

 vided palaeontologically and stratigraphically into systems well 

 defined and equal in value to any system existing in our nomencla- 

 ture of the earth's history. 



Sedgwick's Cambrian comprises two systems, whose individuality 

 is now recognized and admitted by all observers. In one exists 

 the Primordial fauna and in the other the Second fauna. Sedgwick 

 did not find the Primordial fauna and ignored it altogether until 

 the end of his researches in the field ; on the contrary, he discovered 

 and signalized the Second fauna and had it described by McCoy. 

 These facts cannot be disregarded. They solve the question and 

 put aside all the claims of right to name these two systems. To 

 Sedgwick belongs the Second fauna and the rocks containing it ; 

 and there the name of Cambrian must be confined. The other sys- 

 tem, containing the Primordial fauna, was first signalized and de- 

 scribed in America, independently of Sedgwick and of other re- 

 searches made in Europe. Barrande first recognized the great value 

 of the Primordial fauna ; characterized the forms of animals found 

 in it, and its features, which have ever since been accepted and ac- 

 knowledged everywhere. No better judge, consequently, than Bar- 

 rande exists ; and his opinion as to the priority and the importance 

 of the discovery of the Taconic system containing the Primordial 

 fauna must be accepted as a law, as solid as any law or rules made 

 in geology. To Emmons belongs the other system of the primi- 

 tive Cambrian of Sedgwick, and its name of Taconic must super- 

 sede Cambrian with its double meaning. 



I will add that Emmons saw, in 1812, that the lower division 

 of the Cambrian of Sedgwick was, rather more than a division of 

 the third order, a system or great grouping of strata of the second 

 order. He knew no fossils then, and had the merit of being, even 

 stratigraphically, the first discoverer ; finding and proving that the 

 strata below the upper Cambrian form a true system, which is 

 called the Taconic system. (See : Geology of New York, Part n, 

 p. 163, Albany, 1842.) 



So stratigraphically and palaeontologically Emmons has priority 



