10 



of naturalists and poets in all ages. Little was, however, known of their 

 immediate relation with the testaceous mollusks until the appearance, during 

 the last century, of the living Nautilus ; the discovery of this well-known 

 and remarkable shell with the soft parts was hailed with pecuhar interest 

 by the scientific world, because it opened a clue to the history of those ex- 

 traordinary concamerated fossils which are found imbedded in the crust of 

 our globe. The connection between tliis Cephalopod and its chambered 

 engine, at once demonstrated that the hideous Calamary and Cuttle Fish 

 are the living types of the lost race of Ammonites, Belemnites, Scaphites, 

 Turrihtes, and others, whose many-chambered shells remain to us, in a fossil 

 state, in such abundance and variety of forms. 



Some of the naked Cephalopods afford a transition between the two kinds 

 by the formation of an internal rudimentary shell ; the Cuttle Tisli {SepiaJ 

 produces an oval plate ; the Calamary {Loligo) a long horny shell hke a 

 quiU-pen, and the Oni/cJioteutJiis a thin oblong shell Hke a three-edged 

 sword. The more liigUy organized, finned, Cephalopods naturally enjoy much 

 more rapid powers of locomotion than those encumbered with a shell, but 

 are less adapted to dwelling in very deep water. The Sepia is less protected 

 against the attacks of enemies, but it is on the other hand provided with 

 an ingenious mode of seK-defence wliich the well-armed Nautilus does not 

 possess. In the interior of the body is a small bag in which an intense 

 black inky fluid is generated, and the animal has the faculty of discharging 

 it imder any alarm for the purpose of darkening the surrounding water. It 

 is thus enabled to escape the vigilance of its pursuers by darting off in an 

 opposite direction ; and it is said to baffle its enemies by changing colour 

 Hke the chameleon. The paint Sepia, so well known to artists, derives its 

 name from the Cuttle Pish {Sepia); and the celebrated Chinese painting-ink 

 is entirely made from the war-fluid of the Cephalopod. It is a curious 

 feature, too, in the economy of these mollusks that the Nautilus with its 

 protective shell should have no ink-bag, whilst the Belemnite whose shell is 

 enveloped by the mantle is provided with one ; a modification even ensues 

 in the ink-bags of the sheU-less kinds ; those wliich wander defenceless on 

 the bosom of the ocean having a more powerful and intense discharge of ink 

 than those of more soHtary habits wliich seek refuge in the cavities of rocks. 



If any testimony were wanting beyond the only two living witnesses, the 

 Nautilus and the Spirula, to estabbsh the cephalopodic nature of the great 

 fossil Ammonites and their multifarious congeners, we have it in the recent 

 discovery of the soft parts of the Belemnite, an animal long since extinct. 

 A specimen of Belemnite has been lately discovered in the Oxford-clay for- 

 mation, a stratum of very ancient date, with not only the ink-bag, but the 

 muscular mantle, the head, and its crown of arms, all preserved in connec- 

 tion with the Belemnitic shell.* It happened to be the peculiar property 



* Owen, Hunterian Lectures, 1844. 



