UNIVALVES. ARGON AUTA. 69 



The Argonautae are remarkable for their excessive thin, 

 ness, brittleness, and lightness. The A. argo, usually 

 known by the name of the Paper Nautilus, is supposed, 

 in the early ages of society, to have first taught men the 

 use of sails. 



A mucilaginous animal, called Poulpe, is often mista- 

 ken for the paper-nautilus; it is seen sailing on the ocean 

 with its arms erect, and a membrane thrown out between 

 them, by which means it is driven forward, like a vessel 

 under sail. The Mediterranean often has whole fleets 

 of these diminutive navigators floating upon its calm sur- 

 face. 



The color of the Argonautae is mostly blueish, or yel- 

 lowish-white, having the keel often tinged with a brown- 

 ish hue. As to size, the Argonautae differ greatly; the 

 A. argo, for instance, often attains ten or twelve inches 

 in width ; while the A. cornu and A. arctica seldom ex- 

 ceed three or four lines in diameter. 



The Mediterranean and Indian seas produce some va- 

 rieties; others are found at the Cape of Good Hope; and 

 some inhabit the Northern and Greenland seas. 



None of this genus have hitherto been found fossil. 



They are supposed to have derived their name from 

 the Argonauts. 



ARGONAUTA.— Paper Sailor. 



Argo — Paper Nautilus. Cymbium — Minute. 



Vitreus — Glassy. Cornu — Horn-shaped. 



Arctica — Arctic. 



