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BRITISH BELEMNITES. 



Though no complete specimen has occurred of any Belemnitic animal, late discoveries, 

 especially those of Mr. Day in the Lias at Lyme Regis, have established many facts 

 regarding the muscular system of the body, the hooks on the arms, the funnel, ink-bags, 

 eyes, and other parts of importance. Restorations have been attempted at various times 

 by several naturalists since first Miller presented a general sketch showing the affinity of 

 the Belemnite to the Sepiacese. Buckland's figure ( f Bridgewater Treatise,' pi. lxi, fig. 1) 

 represents the ventral aspect of the animal, with funnel, ink-bag, and posterior latero- 

 caudal fins. Only eight arms are distinct in the figure. On the two longer ones are circular 

 suckers. Quenstedt (' Cephalopoden,' t. xxiii, fig. 1G) presents a drawing of the dorsal 

 aspect, showing lateral fins expanded from the alveolar region, with a thin membranous 

 expansion over the fibrous guard, and an equally thin fleshy covering to the anterior part 

 of the phragmocone. The two longer arms are bare, the eight shorter ones have hooks. 

 D'Orbigny sketches a side view, with pointed fins near the extremity of the tail, the 

 Belemnite lying exposed on the back, the two longer arms bare, the others with two rows 

 of suckers each. Ten arms are assigned to the animal by Quenstedt and D'Orbigny, 

 as in the restorations by Owen, 1 which, however, is partly modelled on Belemnoteuthis. 

 This uncertainty in regard to the prehensile organs of the animal has been in some degree 

 removed by the researches of Mr. Day in the Belemnitic beds of Lyme Regis and 

 Charmouth. Several specimens collected by this gentleman have shown in their true 

 relative position the guard, the phragmocone, the anterior extension of the conotheca, and 

 the coronet of hooks which margined the arms. Two of these specimens have been 



figured by Huxley. 2 In one the part of the guard below 

 the phragmocone measures about -th part of the whole 

 animal, in the other about ~th. Von Buch had estimated 

 the length of the animal to exceed that of the shell by eight 

 or ten times ; but if by the term shell we mean to express 

 the whole of the solid calcareous or horny substance, its 

 length is nearly equal to that of the animal, for it reaches, 

 as in the Sepiacese, to the edge of the funnel. The outline 

 of the body of the animal is not yet recovered ; in spe- 

 cimens of the Lias the ink-bag, funnel, and portions 

 of the sclerotic arcs of the eye, are designated by 

 Huxley ; but the muscular substance of the arms, mantle, 

 and fins is untraceable. Such traces do occur in the 

 Oxford Clay in connection with Belemnoteuthis, but the 

 entirely different proportions of the guard in these 

 animals render it improbable that the swimming apparatus could be quite on the same 

 model as in the Belemnite. 



DIAGRAM 15. 



1 Owen, « Phil. Trans.,' 1844. 



Mem. ofGeol. Survey,' 18G4. 



