20 PROF. E. J. GARWOOD AND MISS E. GOODYEAR [vol. lxXlV, 



on the west side of the north-and-south fault which traverses this 

 quarry. Its relation to the Woolhope Limestone is complicated by 

 the presence of the fault and by a covering of Boulder Clay which 

 overlaps from the shale on to the surface of the limestone on the 

 west (PI. V, fig. 1). The shale here appears to be the same as at 

 Sandbanks, near Presteign : it contains similar concretions enclos- 

 ing characteristic trilobites {^Cah/mene hlumenbachii, Dahnanites 

 can d at us), and it may here be lying conformably on the limestone. 

 The second patch, near the Harp Inn. has been much obscured 

 by quarry-tips now almost entirely grassed over; but the traces of 

 fossils found are sufficient to identify it as Wenlock Shale. These 

 occurrences suggest that the inlier was once completely covered by 

 deposits of Wenlock Shale. 



III. The Nash-Scar Limestone. 



The reef-facies of the Woolhope Limestone of the Old Radnor 

 district, described above, reappears at the surface about 3 miles 

 away to the north-east near Woodside, where it ma} r be studied in 

 several old quarries. Still farther nortn-eastwards it forms the 

 picturesque feature of Nash Scar, where it has been extensively 

 quarried along the face of the escarpment for a distance of 600 

 yards, and where (according to J. E. .Davis x ) it appears to have 

 originally reached a thickness of at least 100 feet. At the northern 

 end of the Scar it is cut off by a fault which brings in a small 

 patch of Wenlock Shale against the face of the limestone. Imme- 

 diately north of this, no sections are seen until we reach an 

 exposure of the Pentamerus Grits dipping steeply off the hill on 

 the west side of the road to Presteign. The general sequence of 

 the rocks in this district is fully discussed in J. E. Davis's paper 

 cited above. At the time when his paper was written, however, it 

 must be remembered that the Pentamerus Grit was still considered 

 to be the equivalent of the Caradoc Sandstone. The limestone of 

 Nash Scar is, in every respect, similar to that seen at Dolyhir and 

 Old Radnor ; it contains the same abundant nodules of Solenopora, 

 the same reef-like development of bryozoa, frequently encrusted with 

 SphcBrocodium, also the same general fauna of corals and brachio- 

 pods (including a few rare examples of Cyril na exporrecta and 

 Conchidium knightii), and there can be no doubt that it was 

 deposited contemporaneously with the beds of Old Radnor. The 

 only difference exhibited between the limestones in the two districts 

 is found in connexion with their stratigraphical relationships to 

 older formations. At Nash Scar the limestone dips, to all appear- 

 ance, conformably oft the Upper Llandovery Grit ; while in the Old 

 Radnor district the latter beds are entirely absent, and the lime- 

 stone was accumulated directly upon the Longmyndian rocks. No 

 actual junction, however, is seen at Nash Scar; and the grits at 



1 ' On the Age & Position of the Limestone of Nash, near Presteig-n " 

 Q. J. G. S. vol. vi (1850) p. 434. 



