12 



SHELL GALLERY. 



is exhibited in the upright Case A Dear the entrance to the 

 room. 



The shells of Spirula (fig. 3) have been long known, and are scat- 

 tered in thousands on the shores of New Zealand and other islands 

 in the Pacific Ocean, and they are also found in the Indian and 

 Atlantic Oceans, occasionally drifting on the coasts of Devon and 

 Cornwall. Notwithstanding the abundance of the shells, very few 

 specimens of the perfect animal have been captured. The loosely- 

 coiled shell resembles a ram's horn, and is divided into a number of 

 segments by fine concave partitions, like the shell of Nautilus, each 

 one pierced by a slender tube or siphon. It is placed at the hinder 

 end of the body, and, although usually spoken of as internal,[is 

 not in reality wholly so, as a small portion of it is exposed both in 

 front and behind. Absolutely nothing is known of the habits 

 of this very interesting creature, although probably they are similar 

 to those of other Cephalopods. 



The Nautilus (fig. 4), of which several shells and a perfect animal 



Fiir. 4. 



i J 



The Pearly Nautilus (Nautilus pompilkis). 



a, body ; b, sipbuncle ; c, eye ; d, hood ; e, tentacles ; /, muscle of 

 attachment to the shell; g, siphon. 



in spirit are exhibited, is an inhabitant of the Indo-Pacific Ocean, 

 and differs from all other living Cephalopods in being provided 

 with four instead of two gills, and, instead of eight or ten arms 

 with suckers and hooks, has a number of small retractile feelers. 



