THE MAGAZINE 



OF 



NATURAL HISTORY. 



SEPTEMBER, 1839. 



Art. I. — Extract from the Proceedings of the Zoological Society, on the 

 subject of the relation existing between the Argonaut-shell and its cephalo- 

 podous inhabitant. 



February 26th, 1839. — " A highly interesting and valuable series of speci- 

 mens of thePaper Nautilus (Argonauta Argo), consisting of the animals and 

 their shells of various sizes, of ova in various stages of development, and of 

 fractured shells in different stages of reparation, were exhibited and com- 

 mented on by Professor Owen, to whom they had been transmitted for that 

 purpose by Madame Jeannette Power. Mr. Owen stated that these speci- 

 mens formed part of a large collection illustrative of the natural history 

 of the argonaut, and bearing especially on the long-debated question of 

 the right of the cephalopod inhabiting the argonaut-shell to be considered 

 as the true fabricator of that shell. 



" This collection was formed by Madame Power in Sicily, in the year 

 1838, during which period she was engaged in repeating her experiments 

 and observations on the argonaut, having then full cognizance of the na- 

 ture of the little parasite (Hectocotylus, Cuv.), which had misled her in re- 

 gard to the development of the argonaut in a previous suite of experiments 

 described by her in the Transactions of the Giaenian Academy for 1836. 



" As this mistake has been somewhat illogically dwelt on, to depreciate 

 the value of other observations detailed in Madame Power's Memoir, Mr. 

 Owen observed, that it was highly satisfactory to find that the most impor- 

 tant of the statements in that memoir had been subsequently repeated and 

 confirmed by an able French malacologist, M. Sander Rang. Mr. Owen 

 then proceeded to recapitulate these points. 



" First, with reference to the relative position of the cephalopod to the 

 shell, Madame Power, in her memoir of 1836, describes the siphon as be- 

 ing applied to the part of the shell opposite the involuted spire. M. San- 

 der Rang, who made his observations on the argonaut in the port of Algiers, 

 after having had cognizance of Madame Power's experiments, states, in 

 his memoir published in Guerins's * Magazin de Zoologie' (1837), that in 

 all the argonauts observed by him, the siphon and ventral surface of the 

 cephalopod were invariably placed against the outer wall or keel of the 

 shell, and the opposite or dorsal surface of the body next the involuted spire. 

 " Secondly, with reference to the relative position of the arms of the ce- 

 phalopod to the shell, and the uses of the dorsal pair of arms, usually called 

 the " sails, " Madame Power had described these velated arms as being 

 placed next the involuted spire of the shell, over which they were bent, and 

 expanded forwards so as to cover and conceal the whole of the shell, and 

 from which they were occasionally retracted in the living argonaut : she 

 further made the important discovery that these expanded membranes were 

 the organs of the original formation and subsequent reparation of the shell, 

 and ingeniously and justly compared them, in her memoir of 1836, to the 

 Vol. III.— No. 33. n. s. 2 y 



