Mr. L. Reeve on the Re-calcification of the Shell in Cyprea. 375 
every part of the body; whereas the Mollusca have a muscular 
attachment to the columella, and increase the growth of their 
shell by an exudation, not from the whole body, but from a 
particular organ ;—the mantle bemg the sole agent charged 
with that faculty. It is further ar gued by the same distinguished 
naturalist that the Cowry must lose the power of forming the 
inner chambers of the columella anew, after having once passed 
that early process of development which induces their formation. 
How is it possible, asks M. Deshayes, that the animal can, under 
the circumstances of its nature, secrete a new shell from all parts 
of the body at once, and with all the different phases of colour 
exhibited in the original, when it has reached to an advanced 
condition of its existence ?* 
It is however certain that the Cyprea is paapied to effect a 
very important change in the shell during one or more periods of 
its life; and I think that the fact may be fully established with- 
out prejudice to the excellent arguments of my illustrious con- 
temporary. From the testimony cf a gentleman who worthily 
employs the opportunities afforded him as a Naval Officer to the 
advancement of science, whose veracity is beyond all question, 
and whose communication (given verbatim+) contains nothing 
more than a simple narrative of the phenomena of which he 
was himself an eye-witness, it may I thmk be deduced that it is 
the outer wall of the shell only which is re-constructed, the 
columella with its spiral compartments remaining undisturbed. 
* Animaux sans Vertébres (Deshayes’ edit.), vol. x. p. 486. 
; Lieut. Hankey, R.N., to Lovell Reeve. 
H.M.S. Collingwood, Aug. 6th, 1844. 
My pear Sir,—Will you allow me to offer you a as Peenee on the 
habits of the Cyprea as regards the fact of its making a new shell at an ad- 
vanced age, of which process I have been, myself, in more than one instance 
an eye-witness? I have seen the Cowry craw] into some hollow or sheltered 
place evidently for some predetermined purpose. The growth of the animal 
appears to increase too large for its cell ; it gradually swells and cracks the 
shell, and I think that some powerful solvent or decomposing fluid is dis- 
tributed over the outer surface by the mantle of the fish, for it gets thinner 
in substance and the colours duller in appearance. The shell then entirely 
disappears, the Cowry becomes to all Beecranee A naked mollusk, with no 
other covering than its membranous mantle, and in a short time secretes 
a thin layer of glutinous matter which in a few days obtains the fragile con- 
sistency of shell-lac. From this step its growth is more rapid, and it be- 
comes more and more consolidated into the adult shell. When in the first 
stage of renewal it has the appearance of shell-lac it is always of the Cyma 
form, but I have never succeeded in preserving any specimens in this state 
on account of their extreme fragility. 
Trusting that you may make some use of these notes, and that (as I have 
a good dredge with me) I may, like your friend Mr, Cuming, succeed in 
bringing lome something worthy of notice, I shall conclude myself, my dear 
Sir, yours very truly, Joun B, Hankey, 
