PEOCEEDINaS OP THE GEOLOGICAL SOCIETY. 3 



and the Malverns, from the highest known member rfown to the 

 base of the gneiss, may be thus classified : — A. Pebidian (to be de- 

 scribed hereafter); B. Malvernian — (ct) Dimetian, with associated 

 quartz-felsites and halleflintas (Arvonian), passing down into (b) 

 Lewisian. 



Discussion. 



Dr. Hicks stated that he had always considered the hornblendic 

 series as part of the Dimetian series, and had so marked it in his 

 map, so that he did not think this paper touched his work. He had 

 thought that Dr. Callaway was going to place most of the schist of 

 Anglesey below the above series, but that he did not find stated in 

 the paper. He had for a long time believed that the Malvern series 

 could be correlated with some of the Anglesey rocks. He had long 

 since examined that series. He described some sections exhibited 

 in the Malvern hills, and expressed his disagreement with the 

 author's views. 



Mr. EuTLET asked whether granitoidite was an arkose or not. 

 Prof. Duncan asked what the last speaker would call the rock. 

 He said that Dr. Holl might claim priority in the character of the 

 Malvern rocks. He asked whether felspar similar to that found in 

 the Malvern rocks had been found in Anglesey. He thought it was 

 difficult to distinguish rocks by their mineralogical characters. 



Mr. EuTLEY, in answer to Dr. Duncan, stated that he had not 

 examined the rock, but that the description would lead him to 

 regard it as arkose. 



Prof. BoNNEY explained the sense in which he had suggested the 

 term granitoidite, and said that he could not agree with Dr. Hicks 

 in his reading of the Malvern hills. 



Prof. Hughes asked whether Dr. Callaway had made out the 

 relation of the schists near Craig yr allor, indicated on his ground 

 plan, to those shown in his section, in which schists were repre- 

 sented as faulted against the rocks of the central axis. 



The Peesident, in calling on Dr. Callaway to reply, stated that 

 he thought great caution was needed in identifying rocks far apart 

 by their mineral character. 



Dr. Callaway said he did not attach so much value to minera- 

 logical character as to succession. He had avoided some of the 

 larger questions because he wished to proceed with caution, and so 

 mentioned first those which he was most sure about. He main- 

 tained that the gneiss rocks which he had described were quite 

 distinct from the Dimetian, were of greater antiquity, and were 

 developed in the Menai anticlinal as well as in the central " axis." 

 He had fully accorded priority to Dr. Holl in the character of the 

 Malvern series. Prof. Hughes had missed his chief point, that at 

 Craig yr allor the schists were not faulted against the granitoid 

 rock, but passed up into it. 



2. " Petrological Notes on the Neighbourhood of Loch Maree." 

 By Prof. T. G. Bonney, M.A., P.E.S., Sec. G.S. 



