200 PHYSOPHOR.E. 



Suborder PHYSOPHOR^ Goldf. 



Plii/snphora: Goldf. Handb. d. Zool. 1820. 



Phi/suphorce Agass. Cont. Nat. Hist. U. S., IV. p. 367. 18G2. 



Family AGALMID^ Brandt. 



AgalmiflfE Braxdt ; in Mem. Acad. St. Petersburg, p. 234. 1838. 

 Af/alma- Less. Zooph. Acal., p. 509. 1843. 

 Stcphanomice Less. Zooph. Acal., p. 475. 1843. 

 Slcphanomklm Leuck. ; in Archiv f. Nat., I. p. 312. 1854. 

 Stcphanomidm HuXL. Ocean. Hyd., p. 72. 1858. 

 Agalmidce Agass. Cont. Nat. Hist. U. S., IV. p. 3C8. 1862. 



NANOMIA A. Agass. 



Kanomia A. Agass.; in Proc. Boston Soc. Nat. Hist., IX. p. 181. 18G3. 



Nanomia cara A. Agass. 



Kanomia cara A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 181. 1863. 



This Siphonophore is closely allied to the genus Agalmopsis of Sars, 

 but the nature of the tentacles of the feeding polyps, and the mode of 

 arrangement of the swimming-bells, show undoubtedly that it cannot 

 be jDlaced in the same genus as AgalmopsLs, though closely I'elated to 

 it, as also to Ilalistemma of Huxley. The small size of this species has 

 been of great advantage in enabling us to seize readily, at one glance, 

 the connection between the different parts of this community, while 

 the great size of man}- of the species hitherto observed has always been 

 more or less of a drawback in analyzing the relations of the individuals 

 of the community. 



Fig 331. Tiie float, or swimming-bladder, (I shall use at present 



the nomenclature usually adopted, and afterwards show to 

 what parts these organs correspond in an ordinary Hy- 

 droid,) is a large elliptical cavity (Fig. 331), entirely shut 

 off from the main cavity, which runs from the base of the 

 float, through the whole of the axis of the community. It 

 contains in this genus a bubble of oily sulistance ; the na- 

 ture of the contents of the float varies in different families 

 of Siphonophora^, and this cavity may or may not be closed. In this 

 genus it is closed, and there is no access to the oil-l)ubble from with- 

 out ; the oil-bubble by no means fdls the whole of the cavity of the 

 float. The float is of a brilliant garnet color ; from it hangs the rosy- 

 Fig. 331. Oil-float of Nanomia ; magnified. 



