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S77 



attention to the " Conglomerate" which constitutes the fourth 

 bed in the foregoing series, to which he was disposed to suggest 

 a Permian origin, placed as it is between the "Eed Marls" — 

 here belonging to the Upper Keuper series — and the Pennant 

 rock of the Coal-measures, The "Conglomerate" in question, 

 which is only four feet thick, is made up of rolled pebbles derived 

 from the Pennant, Carboniferous Limestone, and Old Eed. 

 Mr. Symonds being appealed to, was disposed to regard this as 

 a Triassic Conglomerate ; he altogether agreed -with Mr. Lucy 

 as to the Conglomerate occupying the position of a Permian 

 rock overlying the Palfeozic series. 



Prom the tunnel the party proceeded to examine the Camp at 

 Sudbrook, passing by the way the remains of an ancient Chapel, 

 of which very little seems to be known ; it appears to date from 

 the 12th century. The Camp consists of two converging lines 

 of earthwork, with a double vallum and foss, enclosing a trian- 

 gular space, of which the base is formed by the rocky cliffs on 

 the Severn. That this was used by the Romans is certain, but 

 the structure of the ramparts points to an earlier origin. Placed 

 on a projecting point overlooking a flat alluvial plain below, 

 the position seems well selected for the protection of shipping, 

 of which Portskewet was probably a principal station. The 

 connexion of this important passage with the Eoman hues of 

 road on both sides of the estuary, opens up the whole question 

 of the system of fortresses and communications by which the 

 Romans kept in subjection the restless tribes on both sides of 

 the Severn. In illustration of this theme Mr. John Bellows 

 read a paper on the Roman roads on the Lower Severn, pointing 

 out that they formed part of a great system, which can only 

 be understood by tracing the lines of communication to their 

 principal centres, and showing how, by a system of signals and 

 outposts, troops could be rapidly moved and massed on the 

 threatened points. His explanation, too, of the derivation of 

 the names applied by the Romans to the British tribes was both 

 ingenious and instructive. 



From this point the party went to Caldicot Castle, now a 

 mere shell, but stately and picturesque of aspect in its ivy-clad 



