46 TESTACEA. 



This creature feeds readily on mussel, then protruding a real pro- 

 boscis, which is short ; nor is other animal matter rejected 



It is active and vivacious, twisting itself in such a manner as 

 threatens to tear the body from the shell ; meanwhile the long snout is 

 far extended. 



Specimens have survived fifteen months or more in confinement. 



Some of the vermicular tribes prey on the mussel. 



MUREX ATTENUATUS. Plate X. Figs. 5, C, 7. 



Length of the shell four or five lines ; volutions six, ribbed longitu- 

 dinally. Animal a Umax ; a black eye at the external root of each ten- 

 taculum ; snout proportionally shorter than that of the preceding species ; 

 posterior extremity obtuse ; colour of the whole light brown ; marine. 



PIATE X. 



FIG. 5 Murex attenuatus, upper surface. 



6. Under surface of the animal. 



7. Interior of the same, enlarged 



FLATTENED SPIRAL TESTACEA 



Among the more singular arrangements to be instanced of the dis- 

 posal of nature, combining organic with inanimate matter, is lodging a 

 living being in a cavity fashioned as a logarithmic curve, for its perma- 

 nent abode. 



The body of some of these creatures seems so disproportioned to 

 their testaceous dwelling, according to our habit of viewing relative 

 dimensions the gait of the animal so unsteady, from its slight hold of 

 the surface it traverses independently of the respective position of both 

 the tenant and its habitation being so much at variance with convenience 



