On certain Granophyres in Strath (Skye). 523 



polished, and more or less moutonnee. Here also the ice came from 

 a southerly point. These beds are succeeded by Permo-Carboni- 

 ferous glacial beds having an approximate thickness of at least 2000 

 feet, consisting of mudstones with well-glaciated boulders. 



It is extremely probable that the glacial beds of Bacchus Marsh, 

 Wild Duck Creek, and Springhurst in Victoria were of homotaxial 

 if not contemporaneous origin, and they may probably be correlated 

 with the glacial conglomerates at Mount Reid in Tasmania, these 

 correlations being mainly based on lithological evidence. The evi- 

 dence for the correlation of the Bacchus Marsh glacial beds with 

 the erratic-bearing Permo -Carboniferous mudstones of Maria Island, 

 One Tree Point, and Bruni Island in Tasmania, of Maitland, Branxton, 

 and Grasstree in N.S. Wales, and of the Bower River coalfields in 

 Queensland, is that the genus Gangamopteris is distributed sjmewhat 

 abundantly throughout the formations in all these localities. 



This glaciation was probably homotaxial with that of the period 

 of the Dwyka Conglomerate and Ecca Beds of Southern Africa, and 

 of the Talchir Group of the Salt Range of India, the Boulder Beds 

 in Western Rajputana, and the Panjah Conglomerates of Kashmir. 

 In the case of Southern Africa and India, as in that of Australia, the 

 general direction in which the ice moved appears to have been from 

 south to north. In the Bacchus Marsh beds there are at least 9 or 

 10 distinct boulder-beds separated by sandstones and conglomerates ; 

 this may possibly indicate a sequence of glacial periods separated 

 by milder interg]acial periods. The glacial conditions in Australia 

 may have been prolonged into early Mesozoic times, as indicated by 

 the Mesozoic facies of certain plants in the uppermost glacial beds 

 of Bacchus Marsh. 



February 26th.— Dr. Henry Hicks, F.R.S., President, 

 in the Chair. 

 The following communications were read : — 



1. ' On the Structure of the Plesiosaurian Skull.' By Charles W. 

 Andrews, Esq., B.Sc, F.G.S. 



2. ' On certain Granophyres, modified by the Incorporation of 

 Gabbro Fragments, in Strath (Skye).' By Alfred Harker, Esq., 

 M.A., F.G.S. 



The rocks described form a group of irregular intrusions, the 

 largest less than a mile in length, situated in the tract of volcanic 

 agglomerate north and west of Loch Kilchrist. They differ from 

 the normal granophyres, abundantly developed in the neighbourhood, 

 in being darker, denser, and manifestly richer in the iron-bearing 

 minerals, while in places are seen numerous small rock- fragments 

 evidently of extraneous origin. 



The fragments are mainly of gabbro. Closer examination shows 

 that they have been abundantly distributed through the granophyre, 

 but most of them have been more or less completely dissolved. The 

 clearest evidence of this is afforded by the augite of the gabbro, 

 which has been less readily attacked by the magma than the other 



