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have before alluded. It is well displayed along the southern extremity, where 

 it is associated with the well-known pentamerus bed— a deuse mass of fossil 

 shells, which is found in patches over several parts of the country to the 

 west. Lastly, there are the conglomerates which are more closely connected 

 with the Longmynd itself, an exact description of which I have been unable 

 as yet to meet with. One of these is found along the north-eastern flank, 

 and is prolonged as far as Sharpstones hill, near Shrewsbury. It is of marked 

 character, and contains a large number of reddish fragments, as well as of quartz 

 water-worn pebbles. The other is found along the south-western flank, and 

 consists of a vast collection of well rounded quartz pebbles imbedded in a very 

 hard and firm matrix. Many blocks of it may be seen projecting from the 

 sides of the hill north of Plowden station, and are well worth further in- 

 vestigation. A continuation of it is met with in the gorges west of Church 

 Stretton. What may be the exact thickness of this remarkable bed I am at 

 present unable to say. From a walk over its site in company with Mr. Lyell and 

 Mr. Lightbody a few weeks ago, we were inclined to the opinion that its dip 

 and strike corresponded to that of the rest of the Longmynd, and it seemed 

 probable that its thickness was considerable. 



Can any geological fact be more interesting to contemplate than such a 

 conglomerate as this ? Here we see the debris of, as it were, a former world, 

 of rocks which preceded these venerable Cambrians, inconceivably ancient as 

 they are. Here are the most certain evidences that the same forces then as now 

 acted, breaking up the previous rocks, and rounding them by attrition on the 

 primaeval sea beach. 



I do not know whether it is a universal fact, but at any rate it is the case 

 here, that the earliest deposit is almost wholly composed of quartz pebbles, 

 while the later ones, such as that on the south of Longmynd, contains a large 

 number of green and red fragments, probably derived from the Longmynd itself. 

 Are we to draw any inference from this as to the nature of the pre-existing 

 locks? or are the quartz pebbles derived from the veins of that substance which 

 they contained ? 



"We must now for a few moments glance at the country to the west. The 

 most notable feature in the foreground in this direction is the parallel range 

 of the Stiperstones, with their piojecting mass of quartz rock jutting forth at 

 intervals from their crest. For a long time it was supposed that this series was 

 the equivalent of the Lingula flags of Wales, but now it is admitted to be the 

 lower portion of the Llaadeilo group. It is found all along its course in this 

 place to dip at a high angle towards the west, and as these Longmynd rocks 

 do the same it is inferred that they are somewhat if not quite conformable to 

 each other. 



Such a fact would at first sight lead us to suppose that the Cambrians were 

 immediately succeeded by the Llandeilos. But Professor Ramsay has shown 

 clearly that such is not necessarily the case when two distinct strata are found 

 conformable, but that it is quite possible that a long interval may exist between 



