252 PROCEEDINGS OF THE AMERICAN ACADEMY 



Silurian ' division, and which I have named Second fauna. It is then 

 just to recognize this priority, and I tliink it all the more fitting to 

 state it at this time, that it has not been claimed to this day." * 



A more complete demonstration and justification of the priority of 

 the " Taconic System," of its position at the base of all the systems of 

 strata, and of the huge place it holds in the stratigraphic scale, could 

 not be desired. 



It is evident that, if Barrande had seen the memoirs of Emmons 

 when they appeared, he would have used the name " Taconic " to 

 designate all that lower part of the most ancient strata of Bohemia 

 which, having nothing better, he called divisions A, B, and C of the 

 " Lower Silurian." 



There is no doubt, also, that if Sedgwick and INIcCoy had published 

 fifteen years sooner the " Synopsis of the British Palasozoic Rocks and 

 Fossils," Barrande would have recognized the " Cambrian " in his di- 

 vision D of the quartzites with the second fauna. But Barrande pub- 

 lished his " Systcme Silurien de la Boheme" in 1.S52, while Sedgwick 

 first published his great work in 1855, and the Taconic documents of 

 Emmons did not reach Barrande until 18G0. 



These dates explain and answer all objections. There can no longer 

 be any question as to including in one system the primordial, second, 

 and third faunaj ; to do this would be in the actual state of our knowl- 

 edge as great an anachronism as to make one system of the strata con- 

 taining the triassic, Jurassic, and cretaceous faunie. Thus, Linnarson, 

 notwithstanding the slight thickness of the strata of the lower Palaeozoic 

 in Sweden, has not hesitated to recognize three great formations, which 

 he calls Cambrian, Ordovician, and Silurian. This savant was not 

 concerned with the question of priority, nor to know precisely the sig- 

 nification of the term " Cambrian." As to the term " Ordovician," f 

 put forward lately by some English geologists (Prof. Charles Lap worth 

 and others) to designate the rocks containing the second fauna, there 

 is no more reason to accept it than the name " Cambro-Silurian " pro- 

 posed formerly by Sir Charles Lyell. The term " Taconic," brought 

 forward so strikingly by Barrande, is well known to-day ; it has been 

 used in Germany, Norway, Spain, Italy, and France. I have used it 

 in the two editions of my essay of a " Geological Map of the "NVorld." 



* " Documents anciens ct nouvciux sur la Faiine Primonliale ct le Systeine 

 Taconique en Amerique," in Bull. Soc. gcol. du Franco, 2 siir., loin. .will. p. 

 22.3, 1801. 



t Dr. Emmons gave the name " Champlain," in 1842, to the same group of 

 rocks containing tlie second fauna. 



