328 APPENDIX 



the further study of the singular Cambrian forms of 

 the type of Cryptozoon, have opened up new fields 

 of inquiry. 



I think it proper to state, in reference to Dr. 

 Dallinger's footnote on the recent paper of Mr. 

 Gregory, that it must not be inferred from it that 

 Mr. Gregory had access to my specimens from 

 Madoc and Tudor, though he no doubt had excel- 

 lent material from the collections of the Canadian 

 Geological Survey. It might also be inferred from 

 this note that I have regarded the Madoc and 

 Tudor specimens as " Lower Laurentian." The fact 

 is, that I was originally induced in 1865, by the 

 belief of Sir W. E. Logan at that time that these 

 rocks were representatives in a less altered state of 

 the middle part of the Laurentian, to spend some 

 time at Madoc and its vicinity in searching for 

 fossils, but discovered only worm-burrows, spicules, 

 and fragments of Eozoon, which were noticed in 

 the Journal of the Geological Society for 1866. 

 (The more complete specimen from Tudor was 

 found by Vennor in 1866.) On that occasion I 

 satisfied myself fully that the beds are much older 

 than the Cambro-Silurian strata resting on them, 

 unconformably ; but I felt disposed to regard them 



