74 Geological Society. 



stratigraphy and petrology of the above districts, which have led 

 him to the following conclusions : — (1) The granitoid (Dimetian) 

 rocks of Anglesey pass down into an anticlinal of dark gneiss (above) 

 and grey gneiss (below). (2) Associated with the granitoid series are 

 bands of felsite, halleflintas, and felspathic breccias. (3) The suc- 

 cession of gneissic and granitoid rocks in Anglesey resembles so 

 closely the metamorphic series of Malvern as to justify the correla- 

 tion of the two groups. (3) The Pre-Cambrian rocks of Anglesey 

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

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

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

 quartz-felsites and halleflintas (Arvonian) passing down into (6) 

 Lewisian. 



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

 By Prof. T. G. Bonney, M.A., F.R.S., Sec.G.S. 



The author had visited the upper end of Loch Maree and its 

 vicinity with the view of seeing whether microscopic examination 

 threw any light on the vexed questions as to the age of the newer 

 gneiss &c. He described the microscopic structure of a typical 

 series of the Hebridean gneiss, and gave reasons for considering the 

 mass of rock on the right bank of Glen Laggan to be not an intru- 

 sive " syenite," as has usually been supposed, but a mass of the 

 Hebridean gneiss faulted against the newer series. The microscopic 

 structure of the Torridon Sandstones was described : it proves that, 

 as previously asserted, they are made up of the debris of the Hebri- 

 dean series; from this also probably came the materials of the 

 quartzites. By examination of specimens, collected both in Glen 

 Laggan and at other points along the northern escarpment of the 

 newer series, the author showed that its rocks have been rightly 

 called metamorphic ; and then, by comparison of these with speci- 

 mens collected in Glen Docherty, he concluded that the latter 

 belonged to the newer series, and that no part of the Hebridean 

 series reappeared here (which would require a most unusual uncon- 

 formability). On Ben Pyn also he could find no trace of the older 

 series, the rocks there, where not igneous, resembling the newer 

 series, though more highly altered than it is further north. The 

 paper concluded with some remarks upon the bearing of the evi- 

 dence obtained from these studies upon questions of metamorphism, 

 especially as regards its " selective " action. 



3. " On some undescribed Comatulce from the British Secondary 

 Bocks." By P. Herbert Carpenter, M.A., Assistant Master at Eton 

 College. 



