24 argonautidjE. 



degree of independence, that it truly deserves Cuvier's 

 phrase, ' un ver vraiment extraordinaire." " (M idler.) 



In the young state, according to Madame Power, the 

 female Argonaut resembles a little worm, with two rows 

 of suckers along its length, with a filiform appendage at 

 one extremity, and is without a shell. 



Genus ARGONAUTA, Linnseus. 



Vide character of family. 



Hyn. Ocythoe, Bafinesque. Nautilus, Aristotle and 

 PI my. 



Ex. A. Owenii, Adams and Reeve, pi. 2. fig. 1. 1, a. 

 Shell, A. Argo, fig. 1, h. 



The shell secreted by the female Argonaut is thin 

 and semipellucid ; it is embraced by the webs of the 

 dorsal arms which cover the outer surface and keep it 

 in its place. The animals found in these shells are 

 always females, and the apex of the shell is filled with 

 eggs, upon which they sit as if incubating : it therefore 

 seems probable, that it serves as a nest to contain the 

 ova. The shell is one-celled, brittle, horny, slightly 

 flexible when wet, with a large hemispherical nucleus ; 

 there are several species known. 



The Argonaut swims with great velocity in a reversed 

 position with the siphuncle directed towards the fore-part 

 and keel of the shell, and the velated arms firmly embracing 

 the sides of the shell ; it also crawls along the bottom by 

 the contortions of its simple arms, holding the shell back 

 upwards with the membranous arms which are bent back- 

 wards ; there is no muscular or organic connection between 

 the animal and shell, which, when vacated by the Argonant, 

 floats at the mercy of the waves ; while in confinement. 



