^^^'rf^^tfcsw' '< ^^=^--ufe^r 



APPLE TUN-SHELL. Dolimn pnmum. SPOTTED NEEDLE-SHELL. Terebra maeulatn. 



SPOTTED IVORY-SHELL. Eburna areoldta. 



when compared with the magnitude of its dwelling, and in both cases the creature 

 continually advances forward, taking up its residence in a chamber formed in the front of 

 the shell, and closing the passage behind in proportion to its advance. The chief 

 difference, however, between the two is, that the Magilus, being a fixed shell and inhabiting 

 a stony tunnel, needs not the delicately structured shell required by the active nautilus, 

 and therefore merely fills up the useless portions of the shell with solid matter, requiring 

 no hollow chambers and no tube of communication. 



THE three shells represented in the illustration belong to the same comprehensive 

 family. 



The SPOTTED NEEDLE-SHELL, or SPOTTED AUGEE, derives its name from the long and 

 sharply pointed form of the shell. More than one hundred species of this genus are 

 known, all inhabitants of the warmer seas, and the greater part resident within the tropics. 

 In all these shells, the aperture is very small and the canal short. As may be seen by 

 reference to the engraving, the operculum is small and pointed, having the nucleus at the 

 smaller extremity. In many species the animal is entirely blind ; and even in those cases 

 where eyes are present, they are very small, and set at the end of the minute tentacles. 

 The Spotted Needle-shell occupies the extreme right of the illustration. 



The colours of this shell are very pretty. A broken band, composed of very dark 

 and large spots of rich brown, winds round the edge of each spire, and the rest of the 

 shell is covered with bands of pale brown and white, and longitudinal wavy streaks 

 of cream-white. 



