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occnr. the agricultural surface presents a markeil contrast to that of tlio surrounding 

 Silurian, being, in fact, repetitions on a small scale of the large basin of the Devonian 



Let me now speak of its fossils. As a whole, the system was by no means fertile in 

 plants, or at any rate their romains are few and confined to limited areas Among 

 the tiles and the laminated shales of the upper division we have impressions of sea 

 weeds, of marsh plants appareiitly allied to the bulrush and sedge, and of land plants 

 allied to the tree fern. Those generally occur in a fragmentary and carbonised state, as if 

 they had been drifted from a distance to the sea of deposit. In the Fife and Forfar 

 flagstones there is also an abundance of so-called "black-berries" and "raspbeiries," 

 supposed by some to be the spawn of molUisoa, and by others the fruit of some unknown 

 plant. Of its zoopbites, nearly forty species have been found in this country, and 

 thiileen species of echinoderms, the names of which it would be dangerous to the teeth 

 to pronounce. With them have been found many crinoids, generally distinct from 

 those of the carboniferous lime. Its moUusca present a still more formidable list, 

 amounting to about 300 species. Its Crustacea are specially important. In fact, the 

 tile stones constitute a great zone of crustacean life, altogether distinct and peculiar, 

 and which is only beginning to reveal its treasures to palajontologlsts. Notice parti- 

 cularly the Brontes flabellifer, a characteristic trilobite, and the gigantic Pterygotus, 

 called by quarrymen " seraphim," remutely allied to our modern king crab. 



Still more wonderful and much more important are its fishes. The whole system is 

 called by way of eminence the Thaumichthyferous, that is, in plain English, the 

 wonderful fish period. And truly wonderful they were, unlike anything the world ever 

 saw before or since. An extract from H. Miller will make this plain: — "Half my 

 closet walls," says he, " are covered wtih the peculiar fossils of tlie old red, and cer- 

 tainly a stranger assemblage of forms have rarely been grouped together ; creatures 

 ■whose very type is lost, fantastic and uncouth, and which puzzled the naturalist to 

 assign them even their class ; boat-like animals furnished with oars and rudder ; fish 

 plated over like the tortoise, above and below, with a strong armour of bone, and 

 furnished with but one solitary rudder like fin ; other fish, less equivocal in form, but 

 with the membranes of the fins thickly covered with scales ; creatures bristling over 

 ■with thorns, others glistening in an enamelled coat, as if beautifully japanned — all testi- 

 fying of a remote antiquity, a period ' whose fashions have passed away.' The figures on 

 a China vase or an Egyptian obelisk are scarcely more unlike what now exists in nature." 

 Any attempt to describe these would require a volume ; they must, therefore, be "left 

 alone in their glory" for the present. That is the less to be regretted, as you are not 

 likely to meet with any specimens to-day. No doubt there are points, quite within 

 view from Mynydd Troed, where you might expect to find a variety of shells, and 

 perhaps a few worm-tiacks in the tiles, scales, &c., of ilsh, as the Cephalaspis, &c., in 

 the cornstone, and an abundance of instructive nodules in the conglomerate. In the 

 main, however, the rocks about Talgarth were too stormy in their origin, and too 

 deficient in lime, to be likely to afford the fossilist any satisfactory harvest. 



Have I wearied you beyond all endurance ? If not, pray lend me your attention for 

 two or three minutes more. Turn your eyes directly S.E. and look carefully at that 

 stalwart, ragged interloper called Pen-cerrig-calch, which the club visited last year. 

 Speaking of this. Sir E. Murchison says— " I found the culminating point of this arid 

 and lofty mountain 2200 feet above the sea, presenting the limestone not less than fifty 

 feet thick, and occupying an isolated yet distinct escarpment, covered by the true 

 miUstone near 200 feet thick. The chief mass is thick bedded, compact, crystalline, 

 and cream-coloured, without fossils ; but on some of the thinner beds on its southern 

 face, where they disappear beneath the millstones they become oolitic, and contain a 



