MOLLUSCA DIAGRAM 7. 163 



of these arms, and is furnished with a horny beak remarkably 

 similar to that of a parrot. When these animals are alarmed, 

 they discharge into the water a black fluid resembling ink, which 

 is employed in the manufacture of the so-called Indian ink, and of 

 the pigment called Sepia by artists. 



Although our native cuttlefish have no external shell, yet some 

 foreign species known as the Paper Nautilus and Pearly Nautilus 

 are celebrated for the beauty of their shells. 



