372 DK. A. H. COX oisr a longmyndian [Sept. 19 12, 



3. There is also a small patch of Letton Grits and Conglomerates 



which rest with strong unconformity upon the Cambrian rocks, 

 and appear to be of Bala age. 



4. No Llandovery Beds are present. 



5. The Brampton Grits and Conglomerates have been thrust from 



the north-west on to the Cambrian rocks. 



6. Later faulting has brought these beds against Wenlock and 



Ludlow deposits. 



7. The inlieris part of a barrier which has preserved the district on 



the east from the effects of the post-Silurian stresses. 



8. A remnant of Aymestry Limestone is let in between two faults 



at the southern end of the inlier. 



Finally, I wish to take this opportunity of expressing my thanks 

 to Prof. W. W. Watts, for calling my attention to this district, 

 and to Prof. C. Lapworth and Dr. T. P. Sibly for numerous valuable 

 suggestions. 



DlSCUSSIOls^. 



The President (Prof. W. W. Watts) pointed out that the section 

 showing the relation of the rocks was rather a complicated one, and 

 it was not easy to imagine the exact succession of movements to 

 which it was due. If the discovery of an outlier of Bala rocks 

 resting unconformably on the Shineton Shales were confirmed, it 

 would be an interesting continuation of the conditions observable 

 many miles to the north-east at Hoar Edge, along the prolongation 

 of the great Lilleshall-Badnor fault. He congratulated the Author 

 on the evidence that he had advanced as to the identification of 

 Longmyndian rocks in the Pedwardine area. 



Mr. W. G. Peaensides also congratulated the Author upon his 

 choice of so interesting a district, but was of opinion that further 

 evidence was needed upon several of the points raised. When 

 visiting Callaway's locality of Pedwardine with the President last 

 summer, he had had the opportunity of collecting many specimens 

 showing the various stages in the development of Dictyonema, and 

 in examining these he had been much impressed by the unaltered 

 character of the matrix. The specimens of Dictyonema are con- 

 tained in soft, papery, olive-grey shales, and to the speaker it 

 seemed a far-fetched notion to suppose that the adjoining coarse 

 purple and red rocks had been carried to their present position by 

 so drastic a process as the postulated horizontal thrust-plane would 

 demand. A few well-planned excavations might easily decide this 

 question. With regard also to the rocks referred to the Bala 

 Series, he was not quite satisfied. Their local appearance and a 

 strange absence of fine sediment between the pebbles seemed to 

 suggest close affinity to the Llandovery rocks of the Welsh Borders ; 

 but of course, though resemblances count for much, the evidence 

 afforded by the contained fossils should be decisive. 



The Author, in reply, stated that he had closely investigated 

 the Llandovery outcrop near Presteign, and had found considerable 



