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Proceedings of Societies : 



[Jan. 



" 5. He believes that Poll must have been misled when he thought 

 that he had discovered the animal in the egg of an Ocythoe covered 

 with the ' rudiment of a shell,' because all the Molluscans which he 

 has seen in the egg {Cephalopods as well as others) were covered with 

 a well-developed shell, even before all the organs were developed, and 

 the figure which Poli gives of the rudiment does not agree with the 

 nucleus found on the apex of the shell of the Argonauts. Unfortu- 

 nately, none of the eggs of the Ocythoes that have been examined by 

 other observers have been enough developed to show the foetal 

 animal. 



" 6. The different species of Argonauta are said to be inhabited by 

 different species of Ocythoe; but allowing this to be the case, it only 

 proves that each of these genera have local species : the same may be 

 observed with respect to the Hermit Crabs, without proving anything 

 in favour of their being the framers of the shell they live in. 



" 7. That though some specimens of Ocythoe preserved in their 

 shells are marked with cross grooves resembling the grooves on the 

 shell, yet these grooves are only formed by the pressure of the dead 

 animal against the shell ; for the specimens of the animal which are 

 found out of the shell, or which are taken out of the shell while re- 

 cent, are always destitute of these grooves, or of the compressed form 

 of the cavity of the shell. That some specimens which he had re- 

 ceived from the Cape, which had been packed on their sides, had 

 the upper side of the animal smooth and rounded, and the lower 

 flat, and curved like the shell on which it was pressed by its own 

 weighty while a specimen which he had received from the Medi- 

 terranean packed erect, with the mouth upwards, so that the animal 

 was equally pressed against each side of the shell, was flattened and 

 curved on each side, like the specimen examined by M. Ferussac.'* 



Mr. Gray also stated that, so far from the animal using the finned 

 arms as sails, they were the means by which it retained itself in the 

 shell; and he further observed, that it was very difficult to distinguish 

 the species of Argonauta, as they varied greatly in shape, and that on 

 a comparison of many specimens, he had found that the presence or 

 absence of the spines or ears at the back of the mouth were of no im- 

 portance as a specific character, specimens of each of the recorded 

 species having this process developed only on one or the other side.— 

 London and Edinburgh FhiL Mag., and Journal of Scieiice, No, 65— 

 July 1837. 



