462 THE CANADIAN NATURALIST. [Vol. vL 



group. I was the first to point this out. I considered that the 

 evidence afforded by these trilobites was strongly in favour of 

 Dr. Emmons' views, but did not amount to a perfect demonstra- 

 tion. They might constitute a colony, or something analogous 

 thereto. Had no other evidence of the antiquity of the Georgia 

 slates ever been discovered, it is possible that their age might 

 still be disputed. 



About the middle of May, 1860, before I had received Bar- 

 rande's letter above quoted, and in fact before it was written, 

 the trilobites and other fossils in the limestone of Point L^vis 

 were collected. This discovery at once changed the whole aspect 

 of the question. Up to this time the three trilobites of the 

 Georgia slates stood alone, but now a crowd of similar forms 

 came to their assistance. As these new fossils were partly prim- 

 ordial, and in part Lower Silurian types, I assigned to them a 

 position about the horizon of the Calciferous and Chazy forma- 

 tions.* It was at first thought that those which occurred in a 

 peculiar white limestone might constitute a group distinct from 

 the others, and that they might represent some portion of a 

 strictly primordial fauna. It jwas afterwards found that this 

 group was connected with the others, and that the whole belonged 

 to one series. 



On the 12th of July, 1860, I wrote to Barrande, and gave 

 him an account of our discovery. The following are some ex- 

 tracts from his answer : 



" Paris, 19th August, 1860, 

 *' My Dear Sir, 



" Your letter of the 12th July last remained some days at Prague, 

 where it awaited me. I have received it, and hasten to inform you, 

 that I have read it with the most lively interest and the greatest 

 satisfaction. The important discovery which you announce did not 

 surprise me, upon the whole, since, as you have reminded me, I have 

 always hoped for it. I recognize a coincidence, so to speak, provi- 

 dential, hetween that manifestation of the primordial fauna in the 

 environs of Quebec and the moment when the question relative to 

 the three Olenus of Vermont is about to arise. 



* When Sir W. E. Logan first examined these rocks he thought 

 they were older than the Trenton. In his " Preliminary Report" 

 dated 6th December, 1842, he states "of the relative age of the con- 

 torted rocks at Point Levis opposite Quebec, I have not any good 

 evidence, though I am inclined to the opinion that they come out 

 from below the flat limestone of the St. Lawrence." We now know 

 that his first view was the correct one. 



