16 EXTERNAL SHELL. 



detached from the shell by the accident. The vela of the Argo- 

 naut, by clasping and enveloping the shell, had evidently pre- 

 vented the loss of this fragment. It is obvious, also, that the 

 new deposit of testaceous matter was Sucre ted from the part of 

 the animal within the shell, and not from the vela, since the 

 edges of the original shell around the fracture appear exclusively 

 on the outside C. B. ADAMS, Am. Jour. Sci,, 2 ser., vi, 13H, 

 1848. 



Madame Power has seen the fractured shell of an Argonaut 

 partially repaired by membrane in less than six hours. 



The subjoined notes of an accurate modern naturalist afford 

 conclusive evidence of the non-parasitism of the Argonaut. 



On our passage home across the South Atlantic, I enjoyed 

 numerous opportunities of observing the animals of Aryonauta 

 a njo and gondola in the living state, specimens having been cap- 

 tured by us in large numbers by means of a trawl, as they came 

 to the surface of the water at the decline of day in calm weather, 

 in company with Oarinaria, ITyahea. Firola and Clcodora. My 

 observations all tend to prove, as might have been expected, the 

 accuracy of Madame Power's observations on the cephalopodie 

 origin of the shell, and the fanciful nature of the statements of 

 Pliny, Poll, and the poets. 



It is quite true that the female Argonaut can readily disengage 

 herself from the shell, when the velamentous arms become col- 

 lapsed, and float apparently useless on each side of the animal ; 

 and it is equally certain that she has not the power, or, more 

 properly, the sagacity to re-enter her nest and resume the guar- 

 dianship of her eggs. On the contrary, she herself, if kept in 

 confinement, after darting and wounding herself against the sides 

 of the vessel in which she is confined, soon becomes languid, 

 exhausted, and very shortly dies. Numbers of male Argonauts 

 were taken by us. at the same time, without :my shells, and this 

 being the season of ovoposition may account for the 1 females, in 

 such a number of instances, being found embracing their calca- 

 reous shell-nests, which, so ingeniously formed by the instinct of 

 the mother for the protection of her eggs from injury, resemble, 

 in some measure, those nidimental capsules secreted by many 

 marine gasteropoda for the preservation. of the immature embryo. 



