16 THE CANADIAN NATURALIST. [Vol. ix. 



1877 some of the most instructive sections in Nova Scotia, I fail 

 to perceive any good lithological evidence for the Laurentian age 

 of any of the older rocks of the Province, except some of those in 

 Northern Cape Breton, and notably those of St. Anne's moun- 

 tain, which have, apparently on good grounds, been referred to 

 this age by the late Mr. Hartley and Mr. Fletcher. 



One word as to the geological map in ' Acadian Geology,' which 

 notwithstanding its imperfections, needs no apology, when its 

 nature as a mere preliminary and imperfect sketch, the result of 

 private effort and not of a regular survey, is fairly considered. 

 The materials do not exist for a detailed map of the older forma- 

 tions of Nova Scotia. They are being slowly accumulated by the 

 labours of the Geological Survey of the Dominion ; but I do not 

 expect to live to see them complete. Dr. H.'s criticisms, which 

 are so microscopic as scarcely to allow for the accidents of printing, 

 would be unfair, if applied to a map on this scale, even had I been 

 employed to make a regular survey of the country, and had many 

 years been spent in the work. They are specially objectionable 

 when applied to a work executed without public aid ; and when 

 proceeding from a man who has enjoyed opportunities of official 

 employment not accorded to me. 



Note. — Since writing the above, I have received Volume " F " of 

 the Report of the Second Survey of Pennsylvania, relating to the 

 "Fossil Iron Ore Beds " of Middle Pennsylvania. In this report, 

 bedded iron ore. deposits are described as occurring in the Clinton, 

 Lower Helderberg. Oriskany, Corniferous and Marcellus, so that the}"" 

 range, as I believe they do in Nova Scotia, from the Middle of the 

 Upper Silurian to the Lower Devonian inclusive. The principal 

 deposits in Pennsylvania are in the Clinton, Oriskany and Marcellus. 

 In Nova Scotia only small layers are known to me, at Arisaig and 

 East Kiver, so low as the Clinton, and the i)rincipal deposits seem to 

 be Lower Helderberg and Oriskany. The analogy is thus sufficiently 

 close, beds of the age of the Marcellus not having been recognised 

 in Nova Scotia. 



I have used the term "Devonian" in the above paper; but, 

 owing to the doubts and controversies respecting the Devonian rocks 

 of England, I greatly prefer the term " Erian," derived from the 

 great development of the typical rocks of this age on the shores of 

 Lake Erie. 



