ssattmmmma 



108 HONEYMAN GEOLOGY OF A^'TIGONISH COUNTY. 



of the harbour. In the north of the county there are MaHgnant 

 brook, Doctor's brook, Arisaig brook and McAra's brook. 



As a field for the practical geologist this county is of the highest 

 importance. Here we have all the geological formations that are 

 known to exist between the old silurian of our gold fields and our 

 Bay of Fundy triassic, and situated in a line connecting distinguished 

 representatives of both. We appear to have in this county the 

 lineal and direct descendants of the formation, v/hich extending 

 through Guysboro' on the south, has the gold fields of Sherbrooke, 

 Wine harbour and Isaac's harbour — as we have the direct predecessors 

 of Prince Edward Island triassic on the north. The greater number 

 of the formations in the county are represented m Arisaig on Nor- 

 thumberland Strait. In my paper on the Geology of Arisaig I have 

 already explained the character of the group, designating the loAvest 

 member of the series a, and the others in ascending order b, b', c^ u. 

 By comparing a large collection of the fossils of d with the figurcfs 

 of the Upper Ludlow fauna in Nicholson's Siluria, I was convinced 

 that D was equivalent to the Upper Ludlow. Dr. Dawson simul- 

 taneously designated it Lower Helderberg, of which the other is the 

 British equivalent. This was the first step in the proper designation 

 of the Arisaig series, this opinion being subsequently confirmed by 

 Mr. Salter on an examination of my specimens in the exhibition of 

 1862. Dr. Dawson and Prof. Hall had given it as their opinion, 

 that b' was equal to the Clinton, as a characteristic of this is a grap- 

 tolithus not distinguishable from the G. Clintenensis (Hall). Mr. 

 Salter regarding the specimens in the exhibition as G. Ltidensis con- 

 sidered B as Ludlow, while he considered the specimens from c as 

 equivalent to the Aymestry limestone. The fossils of b were not 

 discovered until I made the minute examination of the district of 

 which my Arisaig paper is the record. The bed of graptolltes found 

 in B led me to regard it as of age prior co the Upper Ludlow. 

 Shut up by Mr. Salter's opinion on a, Avhich he was led to consider 

 from the few specimens then collected as equivalent to the May 

 Hill sandstone, I was induced to regard b as the equivalent of the 

 Lower Ludlow. I had thus come to the conclusion, that the Arisaig 

 group was wholly Upper Sikirian. 



Hall's noble work on the Canadian Graptolites, has led me to 

 consider that there is yet something to be done in the correct deter- 



