90 jRej)orts and Proceedings — Geological Society of London. 



2. " The Zonal Classification of the Wenlock Shales of the Welsh 

 Borderland." By Miss Gertrude L. Elles. (Communicated by 

 J. E. Marr, Esq., M.A., F.K.S., F.G.S.) 



This paper deals with the Wenlock Rocks of Builth, the Long 

 Mountain, and the Dee Valley, and establishes the following 

 sequence in these districts : — 



The results obtained by the author completely confirm the work 

 of Tullberg on the Wenlock Shales of Southern Sweden. 



Along the Welsh border the Wenlock Rocks do not cover a large 

 area, but are merely a fringe to the Ludlow Rocks. The former 

 are characterized by graptolites of the priodon-Flemingii type, the 

 latter by those of the colonus type. 



The general structure of the Builth district is a syncline towards 

 the north and north-west part of a series of folds whose axes run 

 north-east and south-west. A later set of movements, along east 

 and west axes, and of later date, lifted the district to the north and 

 north-west of Builth, and, combined with the efi"ect of previous 

 movements and subsequent denudation, caused the exposure in the 



