568 THE UPPER SILURIAN. 



acterlstic of that group, that the most cursory glance would assure a 

 geologist of their probable identity. Yet, as observed by Professor 

 Hall, there is also a mixture of forms looking toward a much lower 

 part of the Upper Silurian series ; and it is worthy of notice that 

 Hall, comparing the fossils with those of New York, gives to the 

 upper members of the series a rather lower or older place than that 

 assigned by Salter in comparison with English fossils, taking as our 

 standard the equivalency of formations in England and America as 

 usually recognised. As the species are in great part different from 

 those of England and America, this slight difference of result may 

 depend merely on defective data, and may be explained when larger 

 materials have been collected, and when we shall be in a position to 

 make allowance for the geographical as well as geological relations of 

 the formations. On either view the equivalent of the Niagara or 

 Wenlock series does not appear, and we may suppose it absent, or 

 that an upward extension of Clinton forms occupies the Niagara period. 



Merigomish. — Dr Honeyman has traced the fossillferous Upper 

 Silurian along the hilly country crossing the upper waters of the 

 rivers of Merigomish, connecting the Arisaig rocks with those next 

 to be noticed on the East River of Pictou. What may be the arrange- 

 ment of the beds in this thick band of slaty rocks is not certainly 

 known, but they appear to contain equivalents of the Upper Arisaig 

 series and also beds with Graptolithus Clintonensls, and others con- 

 taining nodules charged with Lingidce. Below these are beds with 

 Petraia (?) and Cornulites, which may be equivalents of the lowest 

 group at Arisaig. On the north, these rocks are overlaid by the 

 Carboniferous rocks of the coast. On the south, they are continuous, 

 with a broad belt of metamorphic and igneous rocks, the former of 

 similar mineral character, extending across the country to the valley 

 of the St Mary's River. The only locality in which fossils have as 

 yet been discovered in this broad belt is at Lochaber Lake, where 

 Dr Honeyman has found some of the Arisaig fossils and also a species 

 of Zaphrentis, a form which, with some other obscure fossils found at 

 this place, would seem to indicate the presence of beds possibly newer 

 than those of Arisaig. The occurrence of these fossils at Lochaber, 

 as well as the mineral character of the beds, shows that a belt of 

 country about fifteen miles in breadth is here occupied principally by 

 Upper Silurian rocks, probably thrown into a series of synclinal and 

 anticlinal folds, and penetrated by considerable masses and dikes of 

 Syenitic and Dioritic rock. 



East River of Pictou. — We next find the fossiliferous Upper 

 Silurian rocks on the east branch of the East River of Pictou, 



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