Rev. T. G. Bonney — Burrows in Limestone Rock. 487 



apparently, from the form of the end, a burrow, but much weathered. 

 (10). A channel of dubious origin. The other unnumbered burrows 

 extended but a very slight distance into the stone, and presented no 

 special features. I did not think it worth while to make very- 

 precise measurements of the burrows, for at best they could only 

 be approximate, but most of them were a little more than an inch 

 in diameter. 



The second group of burrows was on a somewhat similar block 

 on the eastern face of the G-reat Ormeshead, about fifty or sixty 

 yards from the second gate on the pathway round the mountain. 

 My attention was attracted by some fine burrows on the southern 

 side of the stone, a few inches below the top, and above a roughly 

 horizontal fissure rather more than an inch in greatest width. At 

 right angles to this fissure was a smaller one. To the right of this were 

 two burrows, one small, the other about 2|^ inches deep, and more than 

 an inch in greatest width ; and, on examining them, I found a third 

 immediately behind the latter. To the left was a pair of burrows, 

 one of which was partly concealed in the rock ; in this, and in the 

 third of the other group, fine specimens of Helix aspersa were 

 snugly nestled. Wishing for a specimen of these burrows, and 

 seeing a fair chance of obtaining one in tolerable condition from this 

 boulder, I proceeded to break away some of the stone, and then 

 found that the horizontal fissure extended some inches deep into the 

 stone, narrowing very gradually. On thrusting my fingers into it, 

 I detected other burrows also tenanted by living Helices, and saw 

 several empty shells in the fissure. I then broke away the stone as 

 well as I could, a task of much difficulty with the means at my 

 command. Thus, after putting the fragments together, I obtained a 

 portion of the roof of the fissure, in which, besides those already 

 mentioned, are four distinct burrows, and two circular depressions. 

 Two of these burrows were tenanted by living specimens of H aspersa. 

 For their position and arrangement, see Plate XVII., Fig. 2. Now, 

 these four inner burrows are perfectly smooth, fresh, unweathered, 

 and are stained with the excretions of the snails ; the deepest is 

 about an inch, the shallowest half-an-inch. They are all of them 

 completely protected from the weather; the most remote being 

 nearly four inches from the centre of the large burrow seen from 

 without. In form they coincide with those described by Mr. 

 Darbishire in the following paragraph: "All the holes that I have 

 seen occur in surfaces which have obviously suffered some super- 

 ficial waste. Hence the smaller holes, which usually crowded the 

 surface of a burrowed stone ofi" a recent beach, have generally 

 disappeared, and the fossil-holes lohich remain are the ends of the 

 larger perforations.^^ 



Besides these, I examined a large number of other gToups on the 

 Great Ormeshead, and some on the Little Ormeshead, with the 

 following results. (1). They are clearly the result of the action, 

 mechanical, chemical, or both, of some living agent. Many of them 

 are in positions where rain or wind cannot reach them, run almost 

 vertically up into the rock, and are practically impervious to water 



