60. F. H. Storer—Shell- and Rock-boring Mollusks. 
tion of food by animals should count in favor of the chemical 
view of rock boring. I remember to have said, on that occa- 
sion, that it might as well be argued that tripe could not be 
digested in the stomach of a dog without corroding the walls 
of his stomach as to s say that a marine animal sour not bore 
rocks by chemical means without destroying him 
During the last six or eight years I have had frequent 
opportunity to observe the common whelk (Buccinum) in the: 
act of boring through the shells of mussels and barnacles, and I 
have interrupted his operations, scores of times, at a conceiv- 
able stages of progress. As is well known, the w , having 
boscis whose end is kept continually in contact with one partic- 
ular point on the mussel shell, in such wise that a small round 
hole is there speedily perforated through the caleareous matter. 
he moment the hole is completed the whelk protrudes his: 
_ proboscis still -farther, pretties it into the actual an of the 
mussel, and gradually sucks out and consumes the whole of 
this flesh ; he then passes to another mussel, drills another hole 
in its shell and eats the fleshy contents of the shell, as before. 
t bas been not a little debated whether the process ‘of perfora- 
tion in this case is an act of corrosion by acid or of chipping or 
filing by teeth. Osler (Phil. Mag., eee p. 507) maintained 
long ago that “ the perforation is effec by a succession 0 
strokes, following each other at inter ale. shorter than a second.” 
e says, indeed, that he has distinctly heard these strokes by 
applying to his ear a patella that had a buccinum attached to it. 
e gives Senne figures of the tooth-like, horney points on 
the tongue of cinum, which he compares with a “ center- 
bit ;” and, in like manner, Agassiz and Gould* have figured 
the teeth of natica to show the analogy of the boring apparatus. 
toa “file” or a “rasp.” The powerful muscular development 
of the proboscis a buecinum would of itself lend some counte- 
nance to the idea that it drives a drill. But I must say that to: 
myself the boring act, like the subsequent di; the 
process. at the denticles may aid somewhat in the boring, 
to remove acolan alts bits of loosened or softened shell, and 
that they may afterwards serve to tear off or hook up meat from 
within the mussel seems probable enough, but I am strongly of 
opinion that an ayy clveat is made to act upon the shell 
during the process of boring. It seems not improbable that 
the presence of free muriatic acid might be detected by appro- 
priate chemical experiments made ce large tropical gastero- 
pods. It might even be a one perhaps, to learn some- 
thing in this sense, by studying some one of our own L BpOees 
. id of Zoology, p. 78. 
