182 PECTINIBRANCHIATA.—MURICID&. 
of the shell, after placing the orifice of its own 
body-case against that of its victim.” 
From Mr. Stevenson’s interesting account of the 
erection of the Bell-Rock Lighthouse, we learn that 
the valves of the Mussel are no defence against 
the Dog-Winkle. 
‘When the workmen,” says this gentleman, 
“first landed upon the Bell-Rock, limpets of a 
very large size were common, but were soon 
picked up for bait. As the limpets disappeared, 
we endeavoured to plant a colony of mussels from 
beds at the mouth of the river Eden, of a larger 
size than those which seem to be natural to the 
rock. These larger mussels were likely to have 
been useful to the workmen, and might have been 
especially so to the light-keepers, the future in- 
habitants of the rock, to whom that delicate fish 
would have afforded a fresh meal, as well as a 
better bait than the limpet; but the mussels were 
soon observed to open and die in great numbers. 
For some time this was ascribed to the effects 
of the violent surge of the sea, but the Buccinum 
lapillus | Purpura| having greatly increased, it was 
ascertained that it had proved a successful enemy 
to the mussel. The Buccinum being furnished 
with a proboscis capable of boring, was observed 
to perforate a small hole in the shell, and thus to 
suck out the finer parts of the body of the mussel ; 
the valves of course opened, and the remainder of 
the fish was washed away by the sea. The per- 
forated hole is generally upon the thinnest part of 
the shell, and is perfectly circular, of a champhered 
form, being wider towards the outward side, and 
so perfectly smooth and regular as to have all the 
appearance of the most beautiful work of an expert 
