in Norway and in Canada, 171 



Thus is it not only in Canada, that the position of the rocks of 

 the schistose group is equivocal. Different views prevail as to 

 their age in different countries. In Cornwall, they are considered 

 Devonian, in Scotland, Lower Silurian, and in Bohemia, as in Nor- 

 way, Pre-Silurian. In Belgium, Rhenish Prussia, Westphalia and 

 Nassau, they are by some geologists regarded as Devonian, and 

 by others as belonging to an older formation. In East Russia, 

 on the western slope of the Ural Mountains, they are supposed 

 to represent metamorphic Lower Silurian strata. A dissimilarity 

 of views will probably continue to prevail as to the position of 

 these rocks, until the question is decided, as to what value, in the 

 absence of fossil remains, the petrographical characters of a group, 

 taken in connection with its stratigraphical position, should 

 have in determining its age. Perhaps there prevails at present, 

 too much of a tendency to attribute extraordinary influences 

 to metamorphic agencies. So soon as the true limits and 

 effects of metamorphism are recognized, it will probably be 

 acknowledged that, whatever view may be entertained as to their 

 origin, the schistose rocks above referred to, underlie the Silurian, 

 and all unaltered or metamorphosed fossiliferous strata. Follow- 

 ing close upon more moderate views as to metamorphism, will 

 probably come the recognition of Werner's old rule, as to the suc- 

 cession of these older rocks ; namely that the gneiss groups gene- 

 rally underlie those in which mica schist preponderates, and that 

 the latter are overlaid by argillaceous and cbloritic groups. 

 Thus the ground will be cleared for an impartial investigation into 

 the origin ot the primitive formations. 



Acton Vale, Canada East, 8th April, 1862. 



ARTICLE XVII.— O/i the Mammals and Birds of the District, 



of Montreal By Archibald Hall, M.D., L.R.C.S.E. 



(Continued from page 18.) 



Okd. II. Passeri>ce. 



Fani I. Dentirostres. — Genus Lanius. 



Gen. char. Bill long, compressed, toothed on the upper man- 

 dible, and much bent ; tip of the lower one suberect, and not 

 notched ; nostrils concealed by nuchal bristles ; cere wanting ; 

 nostrals subrotund, half closed by a membrane. 3rd and 4th 

 primaries longest. 



