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unlike Pholas burrows in shape; they were in positions where it 
was wholly impossible that Pholades could burrow, as, for exam- 
ple, driven vertically upwards into overhanging slabs of rock ; 
they were at the bottom of valleys of river erosion, such as 
Miller’s Dale and Tideswell Dale, and in one case on a scarp 
of rock which he was now convinced was artificial. He had 
some additional evidence for their being the work of snails, and 
thought that Helix nemoralis and lapicida as well as H. ad- 
spersa made them. 
Mr NegvILLE GooDMAN described the Monte Pellegrino 
(Sicily) where the stone all over the mountain is perforated, in 
situations where the Pholas could not bore, and in rocks which 
had probably not been submerged since secondary times. He 
quite agreed, from what he had seen, that these burrows were 
the work of snails. 
Mr O. Fisher asked whether possibly the lime was needed 
by the snails. 
Professor HUMPHRY thought that the mode of making the 
hole was mechanical, by the odontophore, rather than by che- 
mical action. 
Mr O. FisHeR exhibited a flint flake from Crayford, which 
was taken from the old brick earth; it was associated with re- 
mains of E. Antiquus and R. Megarhinus, below beds with 
Cyrena fluminalis and Unio littoralis. 
May 13, 1872. 
The PRESIDENT (PROFESSOR HUMPHRY) in the Chair. 
New Fellows elected : 
G. F. Sams, M.A. 
(open \ St Peter's College. 
