14 



Guide to the Invertehrata. 



Stone of Solenhofen, Bavaria ; in the Oxford Clay of Wilts ; in the 

 Kimeridge Clay; and in the Lias of Lyme Eegis, and of Boll, 

 See Wall-case 1 and Table-case 59. 



Cuttle- 

 fishes. 



GALLERY  ^r ^ u 



yjj m W urtemberg. 



{a) OcToroDA. — The Octopods (see Fig. 17, p. 7) are characterized 

 by possessing only eight arms furnished with suckers. The section 

 embraces the Argonaut, or ** Paper IN'autilus," and the Octopus, or 



Fig. 



31. — Animal of Belemnite (re- 

 stored by Owen), a, the eight 

 ordinary arms with hooks at- 

 tached ; t, the tentacular arms ; 

 s, the siphon ; o, the eye ; i, the 

 ink-hag ; ph, the phragmocone ; 

 g, the guard. 



Fig. 



32. — Plesioteuthis {Dorateuthis) 

 Si/riaca,'H.W.,sY). Cretaceous: 

 Lebanon. Wall-easel. Showing 

 internal shell and ink - bag 

 near the centre of body. (Nat. 

 size.) 



"Devil-fish." The Argonaut {Argonauta argo, Linn.), about which 

 many pretty, but fabulous, stories have been told, was the Nautilus 

 primus of Aristotle. The shell is only developed in the female, the 

 male being destitute of any calcareous covering. The Argonaut 

 swims backwards by ejecting water from its funnel, like the 

 cuttle-fishes (Fig. 34). The two supposed ** sails " are the expanded 

 lobes of the pair of displaced and flexed (shell-secreting) arms. The 

 shell is not actually attached to the body, and the animal has 



