310 MOLLUSCA. 



is that of a parasite(l), like the Pagurus Bernhardus, for instance. 

 As it is always found in the same shell, however, and as no other 

 animal is ever seen there(2), although it is very common and so 

 formed as to show itself frequently on the surface, and as the germ 

 of it is visible even in the ovum of the Argonaut(3), this opinion 

 must be considered as highly problematical, to say nothing more 

 of it. 



The ancients were well acquainted with this singular animal 

 and its maneuvres. It is their Nautilus and their Pompilus, 

 Pliny, IX, c. xxix. 



Several species are known, closely resembling each other 

 both in the animal and the shell, which were united by Lin- 

 naeus under the name of Jirgonauta argo, or the Paper Nauti- 

 lus{4). 



Bellorophon, Montf. 



Certain fossil shells, so called, the animal of which is supposed 

 to have been analogous to the Argonauts. They are spirally and 

 symmetrically convoluted, without septa, but thick, and not flutedj 

 the last whorl proportionably shorter(5). 



LoLiGO, Lam. 



An ensiform lamina of horn in the back in lieu of a shellj the sac 

 has two fins, and besides the eight feet promiscuously loaded with 

 little cups on short pedicles, the head is furnished with two much 

 longer arms, provided with cups near the end only, which is 

 widened. The animal uses these latter to keep itself immovable, as 

 if at anchor. The receptacle of the colouring matter is lodged in 

 the liver, and the glands of the oviducts are very large. The co- 

 alescing eggs are deposited in narrow garlands, and in two rows. 



They are now subdivided according to the number and armature 

 of the feet and the form of the fins. 



(1) It is upon this hypothesis that M. Ilaiin. and others have formed the animal 

 Into the genus Octthge. 



(2) All that has been stated to the contrary, even in modern times, is founded 

 upon report and conjecture. 



(3) Toli, Test. Napol., Ill, p. 10. See, also, Ferussac^ Mem. de la Soc. d'Hist. 

 Nat., II, p. 160, and Kanzani, Mem. di Stor. Nat. dec, 1, p. 85. 



(4) Jlrg. argo, Favanne, VII, A, 2, A, 3; — Arg. haustrum, Dehv., lb., A, 5; — Ji. 

 tuberculata, Shaw, Nat. Misc., 995; — A. navicula, Solander, Fav., VII, A, 7; — Jl. 

 Mans, Sol., Fav., VII, A, 6; — .4. Cranchii, Leach, Phil. Trans., 1817. 



(5) Bellorophon vasulites, Monif., Conch. Syst., I, p. 51. See, also, Defrance, 

 Ann. des Sc. Nat., I, p. 264. 



