cyprj:a. 



Plate I. 



Genus Cypr^a, LinnEeus. 



Teda ovata vel ohlonyo-ovata, ventricosa, poUta, interdum 

 nodifera aut costellata, extremUatibus caimliferis ant 

 emarffinatis i spird brevissitm, partini vel omnitio oc- 

 culta; apertura suhcentrali, lonyitudinali, angustd ; 

 colmnelld labroque per totam loiiyitiidinem plus miimsve 

 denticulatis, interdum. at rarb edentulis. 

 Shell ovate or obloug-ovate, ventricose, polished, some- 

 times nodiferous or ribbed, with the extremities 

 channeled or emarginated ; spii-e very short, partially 

 or entirely concealed ; apertm'e neai-ly central, longi- 

 tudinal, narrow ; lip and columella more or less 

 toothed tlu'oughout then- entire length, sometimes, 

 but rarely, without teeth. 

 There is perhaps no group hi the series whose shells 

 have excited more admiration than those of the Ci/praa ; 

 the Cowiy is generally the tu'st to attract the attention of 

 the amateur, and its physiological history offers matter of 

 no less interest to the man of more abstruse habits of 

 enquiry. 



The Cyprcea is a mollusk of veiy peculiar character : 

 ftrst, on account of the different phases presented by its 

 shell at different periods of gi'owth ; and, secondly, on ac- 

 coimt of the curious property which the animal possesses 

 of dissoMng and rene\^'iug its shell. The original gi'owth 

 of the CoflTy is, undoiibtedly, a process of time ; but the 

 re-calcification of a shell at maturer age appears to be the 

 work of a few days only. 



The first stage of advancement produces a simple con- 

 volution of shell around a coliunella axis in the form of a 

 loug di'awn out Bidla, the columella being smooth, the 

 outer lip thin, and the colour usually diffused in bands 

 of waves. In the second epoch of growth the shell solidi- 

 ties, the lip and columella begin to thicken, and present 

 gradual indications of teeth, the teeth become more and 

 more perfectly developed, and the dorsal surface is over- 

 laid with a strong coat of li^id colom'ing matter also dif- 

 fused in obscure bands or waves. The calcifpng energies 

 of the mantle, which, extending in two unequal lobes one 

 from either side of the shell's aperture, have been chiefly 

 exercised dm'ing the second epoch of growth upon the dor- 

 sal sm'face, are now more particidarly dii'ected to the base 



and sides. The teeth are strengthened, the sides become 

 thickened with a rich coating of enamel, and the growth 

 of the shell is completed by a light fabric of coloming mat- 

 ter deposed in lines, blotches, waves, or retieidations, of 

 various hues and patterns. 



The re-calcification of a shell at matm-er age has been 

 a subject of some difference of opinion amongst natm-alists. 

 Brugmere first introduced the fact, and Lamarck says " I 

 possess observations which tend to prove that the Cowiy, 

 arrived at the power of forming a complete shell, has still 

 the faculty of eidarging its habitation, and is then obbged 

 to quit the sliell in order to form a new one. It results 

 from this that the same individiud has the power of form- 

 ing a successive number of shells dmiug both the second 

 and third stages of gi'Owth ; and which accounts for our 

 often meeting with so many different sizes of the same 

 species " ! 



M. Deshayes, after ftirnishing us with an excellent ae- 

 comit of the zoological characters of Cypraa, derived 

 mainly from the observations of M. M. Quoy and Gaunard, 

 m'gues against the possibility of any re-modeUing of the 

 shell taking place, and regards the statement of Lamarck 

 as a theory opposed to the common laws of organization. 

 To the supposition of Brugmere that the Cowries cast their 

 shells after the manner of Crabs, M. Deshayes very pro- 

 perly replies that there can be no analogy between them. 

 The new shell of the Crmtacea is formed by a secretion of 

 equal consistency fi'om every part of the body, whereas 

 the Molhuca have a muscular attachment to the columella, 

 and increase the growth of their sheU 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 fmiher argued by the same distinguished natm-alist 

 that the Cowry must lose the power of fonning the imier 

 chambers of the columella anew, after having once passed 

 that early process of developement which induces then- for- 

 mation. " How is it possible," asks M. Deshayes, " that 

 the animal can, under the circumstances of its nature, 

 secrete a new shell ft'om 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 ?" 



November 1845. 



