Mr. L. Reeve on the Re-calcification of the Shell in Cyprsea. 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 being the sole agent charged 

 with that faculty. It is further argued 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 CyprcBa is enabled 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 of 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 f) contains nothing 

 more than a simple narrative of the phaenomena of which he 

 was himself an eye-witness, it may I think be deduced that it is 

 the outer wall of the shell only which is re-constructed, the 

 columella with its spiral compaitments remaining undisturbed. 



* Animaux sans Vertebres (Deshayes* edit.), vol. x. p. 48G. 

 t Lieut. Hankei/, R.N., to Lovell Reeve. 



H.M.S. Collingvvood, Aug. 6th, 1844. 



My DiiAR Sir, — Will you allow me to offer you a few remarks on the 

 habits of the Cyproea as regai'ds tlie 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 crawl into some hollow or sheltered 

 place evidently for some predetermined purpose. Tiie 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 irgets thinner 

 in substance and the colours duller in appearance. The shell then entirely 

 disappears, the Cowry becomes to all appearance 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 Cymba 

 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 home something worthy of notice, 1 shall conclude myself, my dear 

 Sir, yours very truly, John B. Hankev. 



