ville has grouped together, to form his family Nautilacea, the genera Orbulites, 

 Nautilus, Polystomella, and Lenticulina; and the Baron Cuvier has included with 

 Nautilus, in a more extended family, the Lituacea of De Blainville, and the Ortho- 

 ceratites. But if any confidence is to he placed in the description of the soft parts 

 of Spirula, its organization must differ considerably from that of Nautilus. In the 

 notice of this animal by Lamarck, from which all the subsequent ones appear 

 to have been copied, it approaches much nearer the Cuttle-fish. Instead of being 

 lodged, like the Pearly Nautilus, in the last chamber of its shell, that body is 

 almost wholly buried in the posterior part of the animal, and is only partially 

 visible from without. Moreover, its head is stated to be surrounded by ten 

 arms, of which two, as in Sepia, are elongated, pedunculated, and provided 

 with acetabula at the dilated extremities. The figure which corresponds to this 

 description ispubUshed in the Eneydope'die Methodique (Atlas, Coquilles, pi. 465. 

 fig. 5. a. b.) ; but in the one which appears in the Illustrations to Pe'ron's Voyage 

 (pi. 30. fig. 4.), the pedunculated arms are omitted, and the head is represented 

 surrounded by short conical brachia. As this is the figure which Professor De 

 Blainville has selected for the illustrations of his ' Malacologie' , he had pro- 

 bably some reason for considering it as coming nearest the original, although it 

 is asserted that the figure in the Eneydope'die was engraved from a pen-and-ink 

 sketch taken by Lamarck himself from Peron's specimen. SHght, however, as 

 are both the descriptions and figures of this interesting animal, their value is 

 much diminished by the note* which Professor De Blainville has appended to 

 his character of Spirula, {Malacologie, i. p. 381.) which leads us to hope that 

 when the internal structure of that genus shall be examined, it will also present 

 some interesting modifications of the different organs, and may perhaps be found 

 to connect Nautilus with Sepia. The individual specimen brought to Europe by 

 Peron was found dead, and floating on the sea between the Molluccas and the 

 Isle of France ; it was possibly therefore in a state unfit for dissection. 



The primary arrangement of the class Cephalopoda, so long as it continued to 

 be founded on the anatomical structure of the naked genera only, could not 



* " D'aprfes une lettre 6crite demierement par M. de Freminville a M. Brongniart, il paroitroit que 

 I'animal de la spirule seroit tout different de cette description que nous devons a Pdron. Cependant 

 M. de Roissy, qui a vu I'individu reporte par celui-ci, nous a confirm^ la caractdristique que nous 

 venous de donner." 



