126 Notice of Dr. MantelVs Medals of Creation. 



occurring in certain marbles, as the Sussex and Purbeck ; the 

 fetid emanations produced by friction upon certain Hmestones is 

 due to animal matter. 



Cephalopods. — Dr. Buckland's restoration of the Belemnite 

 under the name of Belemno-sepia* has been fully sustained by 

 the discovery in the Oxford clay, near Chippenham, England, 

 " not only of several examples with the osselet, receptacle and 

 ink-bag in their natural relative positions, but also with the re- 

 mains and impressions of the mantle, body, tentacula, — with 

 their hooks or clasps, and the fins!" From these remains they 

 have been able to draw the figure of the once living animal, 

 with all the appendages true to nature. The fossil ink-bag is 

 sometimes large ; they have been found a foot in length, and it 

 is inferred that the animals were suddenly buried in mud and 

 died instantly, — otherwise the ink would have been ejected, and 

 the membrane would have been destroyed by decomposition. 



In England, the belemnites are confined to the lias, oolite, and 

 chalk ; there are nearly 30 British species. Near Charmouth, 

 two strata of marl on the shore are literally paved with belem- 

 nites. From the fact that many belemnites have Serpulse and 

 other extraneous shells attached to them, it is justly inferred that 

 the ink-bags and other soft parts had decomposed, and the guards 

 lay long uncovered at the bottom of the sea. 



The long celebrated Argonaut or paper nautilus has been at 

 length restored to its true position as a genuine Cephalopod, be- 

 longing to the Octopoda, or those having eight feet or arms. 

 This delicate shell is secreted between thin membranes expand- 

 ed from one pair of the feet, and by them is enveloped during 

 life, but without any muscular attachment ; the shell therefore 

 is readily detached by decomposition after death: "hence the 

 doubts so long entertained as to the relation between the animal 

 of the argonaut and its shell, but which are now set at rest." 



It was formerly supposed that the sepia repeatedly found in 

 the shell was an intruder, but it now appears that it was at 

 home.f In the nautilus, when adult, there are about 35 septa 

 or divisions, with as many chambers, whereas in the Argonaut 

 there are none. 



* Buckland, p. 377. 



t I have seen this Cephalopod in the shell in the Marine Museum in Salem, 

 in Boston, and another in a shop in Boston. — Sen. Ed. 



