SHIZOPODyE. 43 



to them, to M'liich I think the whitish colour of the water 

 may be principally ascribed. Of Cancers we reckoned 13 

 different species, eight having the shape of crabs, and five 

 that of shrimps." Tuchey's Voyage to the Congo. 



These arc all the recorded instances of this very remark- 

 able kind of phosphorescence having been seen ; it is therefore 

 almost unnecessary to say, that the attention of voyagers 

 should be given to it whenever it is met with, and to the 

 animal or animals which appear to cause it, none of which 

 have been satisfactorily described ; this may be done by 

 preserving some of the water until next morning for due 

 investigation, or by straining a portion of it and preserving 

 the filter in a well-closed vessel of common spirits, until 

 subjected to the scrutiny of some qualified naturalist. 



Independent of the animals which operate in a more ge- 

 neral way in the production of the luminosity of the ocean, 

 there are some others Avhich present a peculiar character, 

 and arc moreover of a local nature, at least they have never 

 been observed beyond certain circumscribed limits ; two 

 very remarkable kinds of luminosity of this sort have as yet 

 been noticed. 



The first of these (D.) presents itself to the astonished 

 voyager, under the appearance of thick bars of metal of 

 about half a foot in length ignited to whiteness, scattered 

 over the surface of the ocean ; of these, we perceive some 

 to assume the luminous state and continue it as long as 

 they remain in view, while in others, we witness the 

 luminosity to decline and disappear ; the greater number 

 of these apparently incandescent masses pass close to 

 the sides of the vessel, or follow in her wake, their phos- 

 phorescence being called into activity by coming in contact 

 with her prow or bottom, as that of such as are more distant 

 appears to be, by the conflict of the waves. This appear- 

 ance results from the PjTosoma atlantica, a compound 

 auimal resembling a hollow cylinder of a transparent 

 gelatinous snbstance, iopen at one end, and papillary on its 



