the Inhabitant of the Argonaut. 401 



M. Rang has at the same time observed, that the Octopod 

 with palmated airnis, provided with a shell, does not swim, as 

 the imagination of poets, more than the observation of natu- 

 ralists, has delighted to recount to us, from the highest 

 antiquity, and is too often repeated in our days ; that is to 

 say, by the help of its palmated arms, raised above, the 

 water and serving for sails, or descending into it and acting 

 as oars. Like all the swimming conchyliferous Malacozaria 

 the Octopod places itself with its shell undermost ; but its 

 arms quit the shell still less than in creeping, because, being 

 turned upside down, it would the more easily be separated 

 from it ; and thus locomotion takes place, as in the other 

 animals of this class, by the alternate dilatation and contraction 

 of the mantle, or covering, drawing in and throwing out the 

 water in which the animal is immersed : it then swims back- 

 wards, like the cuttle-fish and calamaries (seiches et les 

 calmars). 



From these recorded facts, of which the authenticity can- 

 not be denied, M. Rang sees, in the employments of these 

 palmated arms to envelope the shell (tet) ; or, to use his own 

 expressions, — 



1st, In the relation that is so well established between the 

 animal and its shell ; 



2dly, In the form of these lobes, which are found in all the 

 species of Ocythoe, and only among them ; 



3dly, In the use of these lobes, as a covering surrounding 

 the shell (tet), in the same manner as in so many other Mol- 

 lusca (lobes which would be useless, if the animal had not 

 had a shell from its birth) ; 



A new argument in favour of the opinion which admits that 

 the Ocythoe is the constructor of its shell. But is not this 

 rather in favour of a contrary opinion ? Indeed, to conclude, 

 as M. Rang has done, from the peculiar provision which an 

 animal has in its organisation for sheltering itself under or 

 within a foreign body, that this body really belongs to the 

 animal, and consequently makes a part of it, would be to use an 

 argument applying evidently just as well to the Pagurusand the 

 Dromiaas to the Ocythoe, and which really is of no weight. 



The long palmated arms of the Ocythoe, perhaps belonging 

 only to the females *, are in the place of the last pair of ap- 

 pendages of the Pagurus and the Dromias, which are organs 



* We throw out this doubt, because, since one of us suggested it fifteen 

 years ago, Mr. Gra}*, having examined ten or twelve individuals preserved 

 in the British Museum, has found them all, if I do not mistake (for 1 quote 

 from memory), to be females ; at least, all those which were still accom- 

 panied by a shell 



