APPENDIX 329 



as more probably of the age of some parts of the 

 Huronian of Georgian Bay, which I had explored 

 with a similar purpose under Logan's guidance in 

 1856. 



[In my subsequent notice of the Tudor specimens 

 in "The Dawn of Life," in 1875, I referred to their 

 age as " Upper Laurentian or Huronian " ; and I 

 may add, that while it is certain that the beds 

 containing them are pre-Palaeozoic, their place in 

 the Eozoic period is still not precisely determined. 

 Work is, however, now in progress which it is 

 hoped may finally settle the age of the " Hastings 

 group" and the old rocks associated with it. I 

 may add that the specimen of Cryptozoon discovered 

 by Mr. Chambers, and of which a portion is repre- 

 sented in the Frontispiece, seems to me to throw 

 a new light on the Tudor specimen. It shows in 

 any case the survival of Cryptozoa similar in form 

 and general appearance to that specimen, as late 

 as the Cambro-Silurian or Ordovician.] 



H. Notes to Appendix, December, 1896. 



While this work was going through the press, I 

 have received the Report of the U.S. Geological 



