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The inhabitant of the Helix ianthina, (lanthina of 

 Lamarck) is possessed of a similar phosphorescent 

 character, and stains the hands of a purple colour, 

 not easily obliterated. This testaceous animal is 

 found in considerable numbers, floating on marine 

 substances. The shell is extremely light, and from 

 its being so fragile, it is seldom found perfect round 

 the lip : among those in our cabinet, there is one of 

 tolerable size, and the shell is entire. The violet 

 helix seems to float and swim at liberty, from in- 

 flating a membranous bag, apparently consisting of a 

 series of minute vesicles. The sea star, found in the 

 Persian Gulf, is said to be circular and very lumi- 

 nous, gleaming like a full moon. Mr. Thompson, in 

 his " Zoological Reseaches," (No. II. April, 1829,) con- 

 siders the phosphorescence of the sea under three 

 sections or classes. The most common or familiar is 

 that exhibited whenever water is slightly agitated by 

 winds or currents, or in the movement of a ship 

 through the ocean : another " resembles the red gold 

 and silver rain of the pyrotechnist." * The former is 

 accompanied by a paler light, transient gleams illu- 

 minating the water to an extent of several feet, some- 

 what resembling the lightning of tropical regions ; 

 diffused flashes issuing from one cloud to another, in 

 constant succession, over the entire visible hemi- 

 sphere. Spallanzani notices a phenomenon of the 

 latter kind, in the Straits of Messina, and by him 

 ascribed to the presence of medusa. The appearance 

 was that of a bright torch of a lively white ; and as 

 the medusa is locomotive, so the light seemed to be 

 variable, being stronger in the systole than the dias- 

 tole. " Sometimes," he observes, " it continues for a 



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