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ABOUT SHELLS. 619 
dedly so. I can hardly doubt that the secret of the power 
which these snails possess is to be sought here. May not 
this bitterness produce a benumbing effect on their prey? I 
have discovered a like bitterness in no other shell, and 
I have collected many species in this way, using my mouth 
as a temporary box. 
Proserpina has a shell of like delicate structure as that of 
Oleacina. Once I found one in close contact with a Mela- 
niella. This, together with its structure, led me to suspect 
that it, too, is carnivorous. Who knows? Will an exami- 
nation of the tongue tell? Will some one try it? I once 
amused myself capsizing these little fellows, and if they did 
not manifest real anger, there was a very good imitation of 
it. Turned on its back, it lashed its tail about violently for 
asnail; or I might say it behaved mulishly and kicked, — 
the organ thus forcibly used being called the foot, I believe. 
The inverted position seemed a painful or disagreeable one. 
I hesitate to record an observation repeatedly made on 
In other species, the said variations are slight. In one or 
more species of Cyclostoma of this latter kind, I have often 
found young individuals considerably larger than any fully. 
grown. There could be no shadow of a doubt that these 
were all of the same species, and not two distinct ones living 
together. Among a dozen or two fully formed shells and 
others nearly grown, all agreeing well in size, one, perhaps 
two or more, incomplete individuals would occur, so much 
larger than all the rest, as to suggest the question, — Why do 
we not find finished shells of this larger size? 
_ Two solutions of this question have presented themselves 
as possible, though neither of them is quite satisfactory- One 
is, that. the animal has power to absorb its shell and recon- 
struct it of a smaller size. The other, which seems more 
probable, is, that these overgrown individuals are abnor- 
