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much larger than any of the eggs that have been found 
to accompany the Ocythoé, in the proportion of at least 
a pea toa pin’s head; Mr. Poli must therefore have 
been somehow deceived when he thought he saw the 
Argonauta developed in the eggs of Ocythoé. The pro- 
bability is, that the Ocythoé chooses the shell of an Ar- 
gonauta as a convenient protection for its spawn, be- 
cause it is light and portable ; and that the sac or mantle 
of Ocythoé in the egg has been taken for the shell. We 
think therefore there is good reason for removing Argo- 
nauta from the Cephalopoda to the Heteropoda, of which 
Order we take the present opportunity of mentioning, 
that we know of no fossil belonging to it. 
