240 . PROF. T. G. BONNEY ON CRYSTALLINE SCHISTS, ETC. 



crystalline schists in this region ; but to reply to the letter which 

 Dr. Geikie had read would be merely to give a repetition of his 

 paper. In this he had dis])roved (as he hoped, satisfactorily) the 

 statements repeated in that letter. He admitted the similarity spoken 

 of by Mr. Eccles, but it was only superficial ; under the microscope 

 the differences were at once visible. He complained that, in 

 Mr. Teall's argument, words had been substituted for things. By 

 this process of reasoning the Devonian and Carboniferous Lime- 

 stones of Britain might be proved to be metamorphic, whereas truly 

 crystalline marbles are quite different. In the Belemnite-series the 

 minerals are not (where authigenous) garnets, staurolites, &c., but 

 dirty hydrous minerals ; it is possible to conjecture what these 

 rocks were, and the organisms are scarcely altered. He could not 

 quite understand Prof, Hughes's points ; but in answer to the notion 

 that we must have connecting-links, he asserted in the present case 

 the totally distinct facies of the two series of rocks. 



