AMERICAN GEOLOGY THE TACONIC QUESTION. 



667 



graywacke group lay below the Trenton in stratigraphic position." 

 In this view Logan at first acquiesced, but applied to the beds as there 

 developed the name Quebec rather than Taconic, subsequently extend- 

 ing the name to the whole belt of Taconic rocks reaching from the St. 

 Lawrence to the Hudson River. 



In I860 Barrande, the eminent Bohemian paleontologist and authority 

 on the Silurian, read before the Geological Society of France a memoir 

 in which he adopted in full the conclusions of Emmons regarding the 

 Taconic system, pronouncing the Georgia, Vermont, trilobites as 

 unquestionably of Primordial age and characteristic of a great Taconic 

 system extending far below the Olenus or J*<ir<i<!o.r/<l<s b zone. 



Subsequent discoveries seemed to show 

 that Barrande was misled through the 

 character of the evidence available, he 

 himself not having studied the question 

 in the field. Be this as it may, his ac- 

 cession to the ranks of the ^Taconists** 

 for a time greatly strengthened their 

 cause, through sheer weight of authority, 

 and did much to complicate the situation, 

 while the use made of his writings and 

 personal letters by Marcou swelled the 

 literature and confused the question until 

 for a time the correct solution seemed 

 hopeless. And here it may he remarked 

 that, however conclusive and convincing 

 the writings of Marcou may appear, the arguments he advanced were 

 founded almost altogether upon the works of others, or. in some cases, 



Fig. 136.— Olenus thompsoni. 



" Subsequent investigations have shewn that the masses in which these fossils were 

 found were but blocks or fragments in a conglomerate, itself a member of the Que- 

 bec group. Billings's conversion was, however, thorough, as shown by the following: 



Montreal, 10th Nov., 1860. 

 My Dear Mr. Meek: 



* * * The discovery of the Point Levi fossils, and also of those published by 

 Hall under the name of Olenus (from Vermont), opens out a new field in American 

 geology. I have received several letters from Barrande on the subject. In the last 

 one received, two days ago, he says that Angelin was then in Paris, and that he had 

 shown him both Hall's figures and mine. Angelin agrees with him that Hall's 

 species, and also mine from limestone No. 1, are of the Primordial type. The Que- 

 bec rocks are undoubtedly the Taconic rocks of Emmons. It will be rare sport if 

 Emmons, after standing alone for 25 years against the majority of the Uite (or at 

 least those who consider themselves the elite) of American geologists, should after 

 all be right. His unfortunate Taconic system has been annihilated and proved not 

 to exist regularly once a year for the last twenty years, and yet it once more raises 

 its head with a new life. I firmly believe that in the main lie is right, although he 

 may be wrong in some minor details. * * * 



E. BlLLINIIS. 



''The Paradoxid.es is a trilobite f ound in Sedgwick's Middle Cambrian, of England. 



