TESTACEA. 37 



rvntly; not quite opaque, but of sensible thickness and consistence. In 

 I >rot ruding, it appears first as a bonier around tin- orifice, then slowly and 

 gradually broadening until do-ing above by meeting of the 



The <-loak is completely withdrawn to concealment with (lie ivtn-.it 

 of the tenant of the shell. 



1 have not l>een able to determine this animal's food with any cer 

 tainty. It is often in active motion, and always Berks the highest pan 

 of its veaael. Observing to renew the water frequently, it survive* a 



: ler.il'le time. When much weakened, it retreat* within, leaving th- 

 rim occupied by the cloak. Numerous empty shells occur in the Seotish 

 was, but very few with the inhabitant alive. 



I'IVTK Yll 



Flu. 15. Cypraa Europata, shell; animal in rvtn-at ; cloak diffusing. 

 |i>. Animal in motion, soon from above. 



17. 1'ii'li r surface. 

 ,1,,-H. 



NATICA At.DKiu. PL:- \ 1 10, Il.l-j. 



Diameter of the shell under half an inch ; the liist \nlut. - the 

 largest, with a deep umbilicus. Colour whitish, speckled brown ; Mirf.i- 

 very beautiful and delicate, of porcelain aspect. 



The animal inhabiting it is of the nature of a Limax, disproportion 

 at ely large compared with it.s dwelling. It extends eleven lines. I: 

 truncate, in front thick, with a duplication of the skin towards each >id-- 

 on the upper surface of the anterior part. Two tentaciila. like white 

 thorns, one-eight h of an inch long, rise from the portion protruding, jui-t 

 at the edge of the shell. The anterior part of the animal is commonh 

 .-mailer and narrower than the posterior, but less so in some s|-.-ii: 

 1'lie whole body is thin, flexible, and much resembling th.it of a 

 1'lanaria ; \et more fleshy, and of a transparent bluish colour. The 

 in its whole extent, is one uniform portion, over part of which the 

 and U-ntaciila proje-t. The motion of the animal i- equal, -\\ilt 



