380 Correspondence — Mr. D. Mackintosh. 



of lime rock of a peculiarly pure composition, whicti liave been par- 

 tially dissolved underneath the thin covering of turf vp^hich overlies 

 the quarries vs^hence they were obtained. At one quarry near Buxton, 

 where a large surface has been bared, the appearance of these stones 

 has given rise to the belief that the surface so bared has been formed 

 by the waves of the sea, and is, in fact, an old sea-beach. This ap- 

 pearance, however, is simply due to modern waste by solution. The 

 author in a lengthy 23aper pointed out the alterations of surface from 

 the underground waste of Gypsum beds, and also from the solution 

 of the matrix of gritstone rocks. It was suggested in discussion that 

 some of the recent earthquakes might have been due to subsidence 

 arising from underground waste. 



COS/E-ESIPOn^ZDIEIsrCZES. 



THE PHOLAS-HO^mG CONTEOVEEST. 



It would appear from a statement lately made by Mr. Binney, 

 r.E.S., of Manchester, that Mr. C. P. Jopling, in 1843, brought 

 forward the existence of what he believed to be burrows of " litho- 

 phag£e" at a height of about 200 feet above the sea, in Fumess, as 

 a proof of a comparatively recent submergence of the land. He 

 referred to the immense boulders on Stainton G-reen, on one of which 

 I have lately found a deep curvilinear groove, in some parts polished 

 and lithodomized. The large specimen I sent to the Geological 

 Society was from an altitude above the sea of about 200 feet ; but 

 some of the small specimens showing a disregard of lithological 

 composition and structure, were from a higher level, and the paper ^ 

 referred partly to instances upwards of 600 feet above the sea. 

 After a prolonged search, I could find none on the summits, or very 

 near to the summits of hills, and nearly all of them were in positions 

 to which rain could not have direct access. In some specimens the 

 holes were bored obliquely into each other, so as to give rise to the 

 appearance of bifurcations ; but, generally speaking, they were 

 exactly of the same form with those found by Mr. Pengelly in 

 Devonshire, and with specimens I afterwards found in Devonshire, 

 and described in the Geological Magazine, Vol. IV., July, 1867. In. 

 Vol. IV. April, 1867, p. 189, you expressed your belief that Mr. 

 Pengelly's specimens agreed perfectly with specimens in the late Dr. 

 S. P. Woodward's cabinet, which contained the valves of Pholas 

 within the cavity. I should like to see the subject fully discussed in 

 your Magazine. I hope your correspondents will perceive that the 

 question is not whether atmospheric action is capable of producing 

 holes in limestone (for this aU will readily admit), but whether it 

 can give rise to the precise form of hole requiring explanation. The 

 advocates of the atmospheric theory ought to bring forward speci- 

 mens of holes exactly agreeing with the alleged P/ioZas-borings, from 



^ See Eeports of the Proceedings of the Geological Society in the June number 

 of this Magazine, p. 282. 



