Nottinghamshire Conchology.—Two specimens of Testacelia Mauget have been found at Welbeck, in Nottinghamshire, by Mr. R. A. Rolfe. In company with that gentleman I found the following species of shells which I have never hitherto found in Nottinghamshire:—Clausilla laminata—one specimen only at Pleasley Vale. Helix lapicida—seven dead specimens at Pleasley Vale, and fifteen at Creswell Crags, and after a long search at the latter place I succeeded in finding one live specimen. Cochlicopa tridens—three 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 oscurus, rare, at Pleasley Vale and Creswell Crags. Helix aculeata, rare, at Creswell Crags. Vertigo pygmæa, rare, at Creswell Crags. Pupa umbilicata, very plentiful in the same locality. I am not aware that either Clausilia laminata, Helix lapicida, or Testacella Maugei have ever before been found in Nottinghamshire, I should be glad to hear if they have been found in other localities.—C. T. Musson, 68, Goldsmith Street, Nottingham,
Borings in Limestone Rocks.—In a geological walk, lately taken across Derbyshire, I kept a close look out for those cylindrical 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 till 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 four 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 will be flat, and, owing to centuries of weathering, their surfaces and edges are much worn and fretted, Crawling along on the grass, and examining the under surfaces of projecting ledges, I was much pleased to find some very fine examples of the burrows or "lithodomous perforations." as they have been termed. They were truly circular, about an inch in diameter, and from one to two inches deep, In the controversy which raged in the "Geological Magazine" these brews were assigned by one party to the marine bivalve shell Pholos, but by ethers to the common land snail, Helix, In the former case they were done when the land was depressed below the level of the sea, and must date back many thousands or tens at 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 burrows on the Druidical stones which form the circle of Arbor Low, seems to me to settle the question in favour of the Helices, for the stones are, undoubtedly, artificially blocked-out masses, rectangular in outline, though they have suffered much from weathering. The snail, it appears to me, decomposes the limestone by means of an acid secretion, aided by the action of its cartilaginous toothed strap or odontophore, (palatial 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 place 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, and its secretions tested for acid by means of blue Huns paper. Here is a task for any patient observers dwelling in mountain limestone districts, I should be pleased to hear if any other observers have noticed these burrows.—W. J. Harrison, Leicester, August 9th.
