I860.] THOST BEEADALBAXE MIXES. 421 



Palceoniscus, &cv among the other classes, the fades of which is equally 

 antique. 



M. Marcou does not, however, rely altogether upon the argument 

 just noticed for the support of his views ; he advances another, which 

 I believe to be equally erroneous. Apparently under the impression 

 that the Permian strata should be referred to the Trins on account 

 of their lithological and mineralogical relationship, he maintains, after 

 depreciating the importance of palajontologieal evidence, that the 

 ensemble of the purely geological characters of a group of strata is 

 of the chief consequence, and suffices alone to determine the age and 

 relative position of tbe group in any part of the world. lS T o\v, as 

 M. Marcou has specialized the Carboniferous and Cretaceous systems 

 as being highly illustrative of the truth of this, I would ask, how we 

 could have determined the age of the Cretaceous rocks of the United 

 States if we had not been assisted by palaeontology? — and who 

 could have told us the age of the Virginian Coal-field, which is de- 

 scribed by Sir C. Lyell as being composed of " grits, sandstones, and 

 shales exactly resembling those of older or primary date in America 

 and Europe, and even rivaling the latter in the thickness of its coal- 

 seams," if we could not have availed ourselves of palaeontological 

 tests ? And if we refer to the investigations of Dr. Geinitz on the 

 Coal-measures of Saxony, we find that by palaeontological evidence 

 he has been able to separate a Permian deposit from those truly Car- 

 boniferous, and also to show good reasons for supposing the lower- 

 most "coal-strata of the same country to be of Devonian age. 

 Other instances arc to be found in formations of all periods. In 

 arguing for the superior importance of palaeontological evidence, I do 

 not, as I have before stated, deny the value of other evidence (indeed, 

 it is highly requisite that all characters should be consulted in settling 

 the age of strata), but I argue against coming back to the old doc- 

 trine of the universality of deposition of one kind of sediment during 

 certain periods ; for the study of organic remains has proved its un- 

 soundness. 



2. Oa the Pocks, Obbs, ami other MnraBAua on (lie Property of (he 

 Maxquess oi Beeaoaxbaxtx in (he Highlands of Scotland. By 

 C. H. Clstav Tuost, Esq. 



[Communicated by Prof. James Niool, F.G.S.] 

 [Abridged.] 

 Mica-schiste, cjv. — On the property of the Marquess of Breadalbane 

 (measuring in a curve nearly LOO miles from east to west, through 

 Perthshire and Argyllshire) mica-schist predominates. The high 

 mountains (Ben More, Ben Lawers, and others) forming the nucleus 

 of the Grampians consist of the Mime rook, which throughout the 



property exhibits its many varieties of mineral character, and in- 

 cludes talc-schists, chloritic schist, and hornblende-rooks, often t<> n 



great extent. In juxtaposition to the mica-schist, in the northern 



