Rev. T. G. Bonney — Burrows in Limestone Rock. 489 



apparent antiquity of tlie deposit, inclined me to the opinion that 

 they were not refuse heaps. This conclusion I now think to have 

 been erroneous. I detected lately in one of the lowest seams in the 

 second set of deposits N. of Tremlyd Point, many bits of carbonized 

 wood, with fragments of bone, pebbles, and stones, some of which ap- 

 peared to have been burnt, together with the right metacarpus of a 

 sheep, perfect but carious. Above this deposit was between eight and 

 nine feet of sand, with some thin seams of mussel shells, about o\ ft. 

 up, capped by a seam nearly a foot thick, just under the sandy 

 surface soil. A little to the north, and still lower down in the cliff, 

 was a thin dark carbonaceous band, in which I found two teeth, 

 very decayed, of a sheep. This, and the first seam also, contained 

 rotten fragments of Littorina, Purpura, Buccinum (?), Cardium, 

 Tapes (?). Still further to the north we have the following section. 

 (1). Sandy soil, with mussel shells, 9 inches. (2). Sand, with frag- 

 ments of mussel shells, 4^-ft. (3). Mussels, with carbonized 

 wood, i-ft. (4). Sand, 1-ft. (5). Mussel shells, 2-ft. (G). Sand, 

 and sandy talus, about 3 feet. (7). Shore a little above high- water 

 mark. Nevertheless, though I have to thank Mr. Darbishire for 

 correcting my error, I yet doubt whether all these deposits " must 

 be set down as appertaining to the most recent human period." 

 That, however, is a point of minor importance. 



P.S. — The above paper was written immediately after making the 

 observations recorded therein. At that time I concluded, from the 

 silence of those who had written or spoken on the subject, whether 

 before the Literary Society at Manchester or the Geological Society 

 of London,^ that no literature existed on the subject. Since my 

 return to Cambridge, in conversation with various friends, I have 

 been directed to sources from which I find myself not alone in the 

 opinion expressed above. See especially the abstract of a paper 

 " On the Agency of Land Snails in corroding and making deep 

 Excavations in compact Limestone Eocks," by Dr. Buckland, in the 

 Proceedings of the Geological Society of London, Vol. iii., p. 430; 

 and a valuable memoir, "Observations sur les Helices Saxicaves du 

 Boulonnais," by M. Bouchard-Chantereaux.^ The author of the latter 

 discusses at considerable length the mode of excavation, and attri- 

 butes it to the action of an acid secreted by the snail's foot. His 

 observations on the form and arrangement of the burrows correspond 

 very closely with my own, and his excellent lithographs of two 

 groups might almost have been copied from some of those near 

 Llandudno. 



ni. — On the Surface-Geology of the Lake-Distkict. 



By C. E. De Range, of the Geological Survey of England and Wales. 



THE following notes were made during a few days' leave of absence, 

 spent chiefly on the Green-slate area of the Lake- district, the 

 beds of which have an east-north-east and west-south-west direction 



1 Quarterly Journal, Vol. xxv. Proceedings, p. 280. 

 ^ Annales des Sciences Naturelles. 4me Ser., Zoologie. Tome xvi., p. 197. 



