CORRESPONDENCE. 309 



Nottinghamshire Coxchology. — Two specimens of Testacella Maugei 

 have been found at Welbeck, in Nottinghamshire, by Mi-. E. A. Rolfe. 

 In company with that gentleman I found the following species of sheila 

 which I have never hitherto found in Nottinghamshire : — CJaimlia 

 laminata — one specimen only at Pleasley Vale. Helix lupicida — seven 

 dead specimens at Pleasley Yale, and fifteen at Creswell Crags, and after 

 a long search at the latter place I succeeded in finding one hve specimen. 

 CocJdicopa tridens — thi-ee specimens at Pleasley Vale. Of species that I 

 have before found in Nottinghamshire, I also found on this occasion Helix 

 caperata, plentiful at Creswell Crags. Bulimus obscurus, rare, at Pleasley 

 Vale and Creswell Crags. Helix aculeata, rare, at CresweU Crags. Vertigo 

 pygmaa, rare, at CresweU Crags. Fupa umbilicata, very plentiful in the 

 same locaUty. I am not aware that either Clausilia laminata, Helix 

 lapicida, or Testacella Maugei have ever before been found in Nottiug- 

 hamshhe. I should be glad to hear if they have been found in other 

 locahties. — C. T. Musson, 68, Goldsmith Street, Nottingham. 



Borings in Limestone Rocks. — In a geological walk, lately taken 

 across Derbyshhe, I kept a close look out for those cyhndrical holes in 

 limestone masses about which an animated correspondence took place in 

 the "Geological Magazine" (Vols. VII. and IX.) a few years ago. Walking 

 at the rate of twenty miles a day does not allow a very close examination 

 of the rocks en route, and I saw nothing of the objects of my search tiU I 

 reached Arbor Low, (or Arbelow as it is sometimes spelt,) the fine 

 Druidical circle which occupies an elevated and lonely hill-top between 

 Hartington and Youlgreave. Here we have a raised ring of earth, about 

 80 yards in diameter, formed of material thrown up from the inside, 

 where, accordingly, there is a corresponding fosse or hollow, mound and 

 hollow being each three or fom- yards wide. In the centre (which is at the 

 natural level) we find oblong masses of limestone, lying in a circle, with 

 a central mass or altar-stone. Whether these limestone blocks were 

 originally set upright or not I do not know ; I should imagine that they 

 were, but now they all he flat, and, owing to centuries of weathering, 

 their surfaces and edges are much worn and fretted. Crawling along on 

 the gi'ass, and examining the under surfaces of projecting ledges, I was 

 much pleased to find some very fine examples of the burrows or 

 " hthodomous perforations," as they have been termed. They were 

 truly chcular, about an inch in diameter, and from one to two inches 

 deep. In the controversy which raged in the "Geological Magazine" 

 these bui-rows were assigned by one party to the marine bivalve shell 

 Pholas, but by others to the common land snail. Helix. In the former 

 case they were done when the land was dejpressed below the level of the 

 sea, and must date back many thousands or tens of thousands of years. 

 If, however, they are the work of Helices, their formation may be 

 comparatively recent ; and, in fact, may still be going on. My discovery 

 of these bm-rows on the Druidical stones which form the circle of Ai'bor 

 Low, seems to me to settle the question in favour of the Helices, for the 

 stones are, undoubtedly, artificially blocked-out masses, rectangular in 

 outhne, though they have suffered much fi-om weathering. The snail, 

 it appears to me, decomposes the limestone by means of an acid 

 secretion, aided by the action of its carfilaginous toothed strap or 

 odontophore , (palatal organ,) which was also the view advocated by Mr. 

 John Rofe. The burrows which I examined were empty, but I believe 

 they are made and used by the Helices as places of hibernation or shelter, 

 and they should be examined again in winter. It is very desirable that 

 the creature should be watched in the act of excavation, audits secretions 

 tested for acid by means of blue litmus paper. Here is a task for any 

 patient observers dwelling m mountain limestone districts. I should be 

 pleased to hear if any other observers have noticed these burrows.— 

 W. J. Harrison, Leicester, August 9th. 



