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MANUAL OF ZOOLOGY. 



several appendages, including i, a single large polypite, nearly central in 

 position ; 2, numerous small gonoblastidia, which resemble polypites, and 

 are termed ' phyogemmaria ; ' and, 3, the reproductive bodies to which 

 these last gi've rise. The tentacles are attached, quite independently of 



f >g- o^- PhysophoridcE. 

 garis (after Gosse). 



a Portuguese man - of- war (Pkysatia utriculus), showing 

 the fusiform float and the polypites and tentacles (after Huxley) ; b Velella -vul- 



the polypites, in a single series along the line where the firm part and limb 

 of the disc unite. There are no hydrocysts, nectocalyces, or hydrophyllia. 

 . . . On all sides the limb is traversed by an anastomosing system of 

 canals, which are ciliated, and communicate with the cavities of the phyo- 

 gemmaria and large central polypite" (Greene). Velella is about two 

 inches in length by one and a half in height. It is of a beautiful blue 

 colour and semi-transparent, and it floats at the surface of the sea, with its 

 vertical crest exposed to the wind as a sail. 



