AND HABITS OF MARINE TESTACEOUS MOLLUSCA. 
507 
expanded cup-shaped extremity. It is furnished with an apparatus of muscles, 
and is probably a gustatory organ, like that already noticed in Patella. The 
extremity may, perhaps, act as a sucker, to seize the food, and convey it to 
the tongue. 
I have observed a third modification of a structure fitted for gorging food, 
in a small Patella from the West Indies ( P . mammillaris, Linn.). There is simply 
a very muscular mouth and pharynx ; and an elastic mass very closely resem- 
bling that in Turbo littoreus ; but neither cartilage, tongue, nor hard parts of 
any description. 
In all the display of instinct there is perhaps nothing more extraordinary 
than that an animal, whose senses appear to be of the most imperfect descrip- 
tion, should laboriously and patiently drill through a shell to obtain its food ; 
and in the whole range of human and comparative anatomy, I am acquainted 
with no structure more complicated than the instrument by which this pene- 
tration is effected. The fact itself is noticed by Pliny ; and although it has 
been questioned by some modern naturalists, while I am not aware that any 
have confirmed it by their own observation, it may yet be witnessed on the 
shores almost at any time. One of our most common littoral mollusca, Buc- 
cinum lapillus, feeds in this manner ; and whenever it is seen attached to an- 
other shell-fish, with the foot slightly projected and expanded, a more or less 
advanced perforation will be found. On the shores at Swansea, its common 
prey is the muscle ; and it sometimes, though rarely, attacks the oyster and 
anomia. Around Falmouth, it feeds chiefly on the limpet, but will occasion- 
ally be seen upon Turbo, Trochus, Nerita, and even its own species*. 
The perforation is effected by a succession of strokes, following each other 
at intervals shorter than a second. I have distinctly heard them by applying 
to the ear a Patella which I had carefully removed from the rock, with a Buc- 
cinum attached to it. The process is extremely slow. I have found it still 
incomplete after having watched it for some hours. When the perforation has 
been effected, the prey is not immediately destroyed by any poisonous secre- 
* Mr. Dillwyn’s observations lead him to suppose that Bwccinum lapillus commonly feeds on the 
Balanus. I have never seen anything to confirm this opinion, and believe the prey to be much too 
small for the full-sized Buccinum ; but I constantly observe small specimens in situations where they 
could scarcely obtain any other food. 
