428 Corres2Jondence — Prof. T. G. Bonney. 



remained above sea-level or else have been shielded by some pro- 

 tective covering during both subsidence and elevation," a view from 

 which I do not yet see the slightest reason to waver. If the country 

 is a cold one, such for example as we might imagine during the 

 retreat of a continental covering of ice from the face of Sweden, and 

 depression were taking place, coast-ice, it seems to me, would grind 

 every furrow from the surface of the rocks, as they gradually sank 

 down at any particular time, the abrading action taking place from a 

 level above that of high water to one below low water, and every 

 portion of the surface of the country being many thousands of years 

 in sinking through the abrasion region. On elevation this erasing 

 action would be repeated. If the country were not a cold one, 

 atmospheric agencies, a continual exposure to an artillery of pebbles, 

 the grinding of sand, and like causes, would, according even to the 

 most modest calculations, have sufficient time for the production of a 

 similar result. John Milne. 



Yedo, June 17, 1878. 



THE QUAETZITES OF THE BTJjSTTER CONGLOMEEATE. 



Sib, — As I happen to be very familiar with the quartzites of the 

 Bunter Conglomerate of the Midland Counties, may I be allowed to 

 question the correctness of one or two statements which have been 

 lately made in the pages of the Geological Magazine. 1. I can- 

 not admit that the typical quartzite of this Conglomerate is litho- 

 logically identical with that from Budleigh Salterton. 2. I greatly 

 doubt whether the fossiliferous pebbles from the Birmingham Drift, 

 now in Jermyn Street Museum, have been derived from the Bunter 

 Conglomerate. At any rate, the rock, though a quartzite, does not 

 appear to me that of the Bunter pebbles : it more nearly resembles 

 that from the Lickey. 3. I have many times searched for fossils 

 in the pebble beds of Staffordshire, and have only twice found them': 

 these were obscure annelid burrows. Hence I cannot admit that 

 there is any pal^ontological identity with the Budleigh Salterton 

 rock. From physical considerations it would require very strong 

 evidence to induce us to believe that the Midland Counties pebbles 

 came from S. Devon. I have no doubt Professor Hull is right in 

 assigning to them a northern origin (Permian and Trias of Midland 

 Counties, p. 60). I have myself identified them in more than one 

 place in Scotland. For example, they abound in a conglomeratic 

 red sandstone of Lower Carboniferous age in Arran, mixed, how- 

 ever, with fragments of schist, greywacke, etc. These softer rocks 

 have almost invariably perished on tlie southward journey — so that 

 it is a case of survival of the most durable. T. G. Bonney. 



St. John's College, Cambridge, Aug. 12. 



