Tachylyte from Victoria Park, Whiteinch. 143> 



partly or entirely eroded before the deposition of the Westleton 

 beds. In the north, where the present series dies out, they come 

 in contact with the so-called Weybourn Crag, which the author 

 supposed to be the equivalent of the Norwich Crag. A similar 

 discordance has been noted between the Westleton beds and the 

 overlying glacial beds, so that the former mark a distinct period, 

 characterized by a definite fauna, and by particular physical con- 

 ditions. The Westleton beds being marine, and the Mundesley 

 feeds estuarine and freshwater, the author proposed to use the 

 double term to indicate the two facies, as has been done in the case 

 of other deposits. But these facies were found to be local, and the 

 most persistent feature of the beds is the presence of a shingle of 

 precisely the same character over a very wide area. By means of 

 this the Westleton beds can be identified far beyond East Anglia, 

 and where there is no fossil evidence, and they throw considerable 

 light on important physiographical changes. 



The author described the composition of the shingle, which, 

 unlike the glacial deposits, contained pebbles of southern origin. 



The paper concluded with a list of fossils, excluding those of the 

 Forest-bed (the stumps of which, the author considered, were 

 frequently in the position of growth). Should the Forest-bed 

 eventually prove to be newer than the Chillesford beds, it was 

 maintained that the former must be included in the Westleton 

 series, and its flora and fauna added to the list, whilst if, on the 

 contrary, the Forest-bed should be proved synchronous with the 

 Chillesford beds it must be relegated to the Crag. 



The second part of this paper will treat of the extension of these 

 beds into and beyond the Thames Valley, and on some points con- 

 nected with the physical history of the Weald. 



June 19.— Prof. J. W. Judd, F.E.S., Vice-President, 

 in the Chair. 



The following communications were read : — 

 1. " On Tachylyte from Victoria Park, Whiteinch, near Glasgow.' 9 

 By Frank Eutley, Esq., F.GLS. 



This paper dealt with the microscopic characters of certain thin 

 tachylytic selvages occurring on the margins of white-whin (basalt) 

 veins which traverse Carboniferous shales in Victoria Park, and 

 which have already been described in some detail by Messrs. John 

 Young and D. Corse Glen. The white-whin veins, which sometimes 

 are not more than an inch in breadth, are found to become gradually 

 more vitreous in passing from the middle to the sides of the veins. 

 Near the margin they become densely spherulitic, the spherulitic 

 band on either side of the vein being followed by a less spherulitic 

 and more glassy band, the vitreous matter of which appears nearly 

 or quite colourless. A sharp but irregular boundary-line follows, 

 beyond which lies a band of a more or less deep brown or coffee- 

 coloured glass which the author considers to have resulted from the 



