^02 Geological Society. 



Conglomerate of Staffordshire. After a sketch, of matter already 

 published, he gives additional particulars of the lithology of the 

 pebbles, more especially of the f els tones and of some rather compact 

 dark rocks. Of the former he has now obtained about thirty 

 varieties : orthoclase-felsites and porphyrites, some with, others 

 without quartz ; several contain tourmaline, which sometimes 

 has replaced biotite, sometimes felspar. One pebble exhibiting 

 reddish spherulites in a dark matrix, once doubtless glassy, but 

 now devitrified, is not like any British rock known to the author. 

 Of the dark pebbles, some are fine-grained quartzites blackened 

 with opacite ; others, varieties of ' schorl-rock,' and two (which 

 Dr. G. J. Hinde has kindly examined) are radiolarian cherts, which, 

 however, cannot be more precisely identified. 



The mode of transport and source of the pebbles are next con- 

 sidered. The reasons, already published, for a fluviatile, as opposed 

 to a marine, origin are briefly summarized. If the former be 

 accepted, certain conditions must be satisfied, which bear directly 

 on the position of the source. These beds represent the destruction 

 of large masses of rock. If brought by rivers, those must have 

 been important and powerful, of a continental rather than an 

 insular type. Hence the necessary physical conditions exclude 

 limited districts near the Midlands, such as the Wrekin, Lickey, 

 rlartshill, and Charnwood, even if they included (which is not the 

 case) the right types of rock. As regards the Longmynds, their 

 argillites, if they occur, are not common ; their conglomerates do 

 not exactly resemble the Bunter pebble-beds ; their ' Torridonian ' 

 is a quartz-rhyolite rather than a quartz-felspar grit. The rocks 

 required cannot be supplied from either Wales, the Lake District, 

 or the Pennine Range, and we have no reason to suppose them con- 

 cealed uuder Eastern and South-eastern England. We have there- 

 fore to choose between a southern and a northern source. Cornwall 

 and Devon might perhaps furnish the schorl-rocks ; possibly also one 

 or two varieties of felstone (though this is doubtful) and the right 

 quartzites and quartz-felspar grits occur in the Budleigh Salterton 

 pebble-bed. But the characteristic flat ellipsoidal pebbles of grit, 

 dominant here, arc not found in the Midlands. Physical conditions 

 also seem opposed to a northward flow of the rivers of Britain in the 

 earlier part of the Trias. In Scotland, however, we find the right 

 varieties of quartzite, the Torridonian grit, and many felstones. some 

 apparently identical with, others closely related to, those in the Mid- 

 lands. The rarity of tourmaline-rocks in that region is the only 

 diffieulty in looking to it or its vicinity for the main source of these 

 pebbles. 



2. ' Further Evidence of the Skeleton of Eurycarpus Oweni.' By 

 Prof. H. G. Seeley, F.U.S., F.L.S., V.P.G.S. 



