ARMS OF THE NAUTILUS. 



173 



the original formation and subsequent reparation of the 

 shell ; and ingeniously and justly compared them in her 

 memoir (1836) to the two lobes of the mantle of the 

 cowry. " These facts," observes Professor Owen, "^ are 

 described as the result of actual observation ; but Ma- 

 dame Power, entertaining the common belief of the action 

 and use of the velated arms in the sailing of the cepha- 

 lopod, enters into considerations respecting their pro- 

 portional strength in relation to that hypothetical office. 

 The subsequent observations of M. Rang have fully 

 confirmed the accuracy of Madame Power's description 



Argonauta argo. 



of the relative position of the so-called sails of the 

 argonaut to the shell ; and he has published some 

 beautiful figures illustrative of this fact." Of these 



