part 1] OX THE GEOLOGY OF THE OLD RADNOR DISTRICT. 2i> 



Plate IV. 



View, looking- northwards, of the fault-plane forming the eastern end of 

 Yat Quarry. This fault brings up the Pre -Cambrian rocks on the 

 right, from the top of which the limestone has been removed by 

 quarrying. (This old quarry is shown on the sky-line in PI. Ill, a 

 little to the right of the centre of the picture.) One of the curved 

 north-and-south thrust-planes is seen on the left. 



Plate V. 



Fig. 1. View looking southwards, showing the main fault which traverses 

 Dolyhir Quarry in a north-and-south direction. This fault has 

 thrown down the limestone on the west, which is there worked at a 

 lower level. A patch of Wenlock Shale (W.S.) is also let down 

 against the fault, and can be seen in the centre of the picture near 

 the top of the cliff. 

 2. One of the east-and-west ' tear '-faults, showing a horizontally- striated 

 surface, Strinds Quarry. 



Plate VI. 

 Calcareous algas from the Old Radnor Limestone. 



Fig. 1. Soleiwpora gracilis, sp. nov. X 25. Longitudinal section, showing 

 lines of growth and pseudosporangia. 



2. Soleiwpora gracilis. X 25. Showing enlargement of cells in contact 



with a foreign body. 



3. Sphseroc odium gotlaudicum Rothpletz, coating surface of bryozoa. 



X 10. 



4. Sphasrocodium gotlaudicum, showing traces of branched cell-threads. 



X45. 



Plate VII. 



Geological map of the Old Radnor Inlier, on the scale of 6 inches to the mile 

 or 1 : 10,560, with an inset-map of the Strinds -Quarry area, on the 

 scale of 25 inches to the mile or 1 : 2535. 



Discussion. 



Dr. J. V. Elsdex said that he had recently been over the ground 

 described in the paper, and one of the Authors had been good 

 enough to show him the critical sections upon which their con- 

 clusions had been based. The evidence was clear and incontro- 

 vertible so far as the main facts were concerned, and he could 

 suggest no alternative reading. Earlier workers had been mistaken, 

 both as to the age of the rocks and as to the structure of the district. 

 Some of their errors might conceivably have been due to the 

 absence of good exposures. Quarrying had been in active progress 

 in this area for many years, and evidence available at any particular 

 time might be subsequently buried beneath the quarry-tips. For 

 that reason it was gratifying that this paper had been brought before 

 the Society, and that a detailed record of existing evidence would 

 now be preserved. With regard to the alleged metamorphism 

 described by earlier writers, too much importance had clearly been 

 ascribed to the proximity of the igneous intrusions of S tanner and 

 Hanter Hill. There was. so far as the speaker knew, no evidence 



