530 Illustrated Zoological Notices. 



carbonate of lime. It is therefore not unlikely that the 

 glands necessary for secreting this substance do not exist, at 

 least to an equal degree, in those parts of the mantle marked 

 by the bands. This, however, is but a conjecture, and only 

 important as connected with a subject which deserves a much 

 more accurate investigation than has ever yet been bestowed 

 upon it." (T. B. 9 Zool. Joum., vol. i. p. 94?.) 



Now, upon the assumption that the Ocythbe is the real con- 

 structor of the Argonaut, if we give it credit for the same anxiety 

 to repair apertures in the body of its shell as that evinced by 

 the animal of Helix pomatia, the former Mollusc would cer- 

 tainly of the two appear the better adapted for effecting such 

 an object, since it not only has no organic attachment to its 

 habitation, but has even the power of detaching itself alto- 

 gether ; a circumstance which, upon a prima facie view, would 

 certainly indicate a greater freedom of accommodating its 

 secreting organ to injured parts than if the body of the Cepha- 

 lopod were confined, as in the case of the pearly Nautilus. 

 Dr. Leach, in a paper published in the Philosophical Trans- 

 actions for 1817, thus alludes to Mr. Cranche's statement 

 respecting the power which the Ocythbe possesses of quitting 

 its shell : — 



" The observations made by the late Mr. John Cranche, 

 zoologist to the unfortunate Congo expedition, have cleared 

 from my mind any doubts on the subject. In the Gulf of 

 Guinea, and afterwards on the voyage, he took, by means of 

 a small net (which was always suspended over the side of the 

 vessel), several specimens of a new species of Ocythoe, which 

 were swimming in a small Argonauta on the surface of the 

 sea. On the 13th of June, he placed two living specimens in 

 a vessel of sea water; the animals very soon produced their 

 arms, and swam on and below the surface, having all the 

 actions of the common Polypus of our seas, by means of their 

 suckers, they adhered firmly to any substance with which 

 they came in contact, and when sticking to the sides of the 

 basin, the shell might be completely withdrawn from the 

 animals. They had the power of completely withdrawing 

 within the shell, and of leaving it entirely. One individual 

 quitted its shell and lived several hours, swimming about, and 

 showing no inclination to return into it ; and others left the 

 shells as he was taking them up in the net. They changed 

 colour like other animals of the class Cephalopoda: when at 

 rest, the colour was pale flesh-coloured, more or less speckled 

 with purplish; the under parts of the arms were bluish grey, 

 the suckers whitish." 



There is one fact which I cannot help regarding as highly 

 favourable to the opinion of the Ocythbe being a parasite, and 



