38 



coating of enamel, and the growth of the sliell is completed by a light 

 fabric of colouring matter deposed in lines, blotches, waves, or reticulations, 

 of various hues and patterns. These are not, however, the only physiolo- 

 gical changes that take place in the Cowrey. From observations made by 

 a gentleman who worthily employs the opportunities afforded him, as a 

 Naval officer, in the pursuit of science, I have strong reasons for believing 

 that there is some truth in the argument set forth many years since by 

 Bruguiere and Lamarck, relative to the Cyj^raa possessing the faculty of 

 partially dissolving and rene\\dng its shell after having arrived at maturity.* 



Lamarck says in reference to the re-calcification of the Cyprma shell, " I 

 possess observations which tend to prove that the Cowrey, arrived at the 

 power of forming a complete shell, has still the faculty of enlarging its 

 habitation, and is then obliged to quit the shell in order to form a new one. 

 It results from this that the same individual has the power of forming a 

 successive number of shells during both the second and third stages of 

 growth ; and which accounts for our often meeting with so many different 

 sizes in the same species '' ! 



M. Deshayes argues against the possibility of an entire re-modelling of 

 the shell, and justly regards the statement of Lamarck as a theory opposed 

 to the common laws of organization. To the supposition of Bruguiere 

 that the Cowries cast their shells after the manner of Crabs, M. Des- 

 hayes very properly replies that there can be no analogy between them. 

 The new shell of the Crustacea is formed by a secretion of equal consistency 

 from all parts of the body, whereas the Mollusca have a muscular attach- 

 ment to the columella, and increase the growth of their shell by an exuda- 

 tion, 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 tlie 

 same distinguished naturahst that the Cowrey must lose the power of form- 

 ing 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 circum- 



* Lieut. J. B. Hankey, E.N., to Lovell Reeve. 



Will you allow me to offer you a few remarks on the habits of the Cj'prfca as regards the fact 

 of its making a new shell, at an advanced age, of which process I have been myseK in more than 

 one instance an eye-witness. I have seen the CovATcy crawl into some hollow or sheltered jjlace, 

 evidently for some predetermined purpose. The growth of the animal appeal's to increase too 

 large for its cell; it gradually swells and cracks the shell, and I think that some powerfid solvent 

 or decomposing fluid is distributed 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 disappeai-s, 

 the Cowrey becomes, to all appearance, a naked mollusk, wAh no other covering than its mem- 

 branous mantle, and in a short time secretes a thin layer of glutinous matter which in a few days 

 obtains the firagile consistency of shell-lac. Prom this step its gro\\i:h is more rapid, and it 

 becomes more and more consolidated into the adidt shell. AVhcn in the first stage of renewal it 

 has the appeai'ance of sheU-lac it is always of the C'ymba form, but I have never succeeded in 

 preserving any specimens in this state on account of their extreme fragility. 



Il.M.S. Colliugwood, August 6th, 1844. J .B. H. 



Conchologia Icoiiica, Cypr/EA Plate I. 



