ORDER CEPHALOPODA. 21 



little barks on the surface of the waters of the Mediter- 

 ranean. The words of the ancient Roman naturalist, 

 Pliny, give a pleasing description of its habits. " Among 

 the principal miracles of nature," says he, " is the animal 

 called Nautilos, or Pompilos : it ascends to the surface 

 of the sea, in a supine posture, and, gradually raising 

 itself up, forces out, by means of its tube, all the water 

 from its shell, in order that it may swim more readily ; 

 then, throwing back the two foremost arms, it displays 



THE ARGONAUT, OR PAPER NAXTTILUS. 



between them a membrane of wonderful tenuity, which 

 acts as a sail, while, with the remaining arms, it rows 

 itself along, the tail in the middle acting as a helm to 



