214 



PORPIT^. 



Suborder PORPIT^ Goldf. 



Porpilm Ooi.DF. Handb. tier Zool. 1820. 



PorpiUe and Phi/.talke Agass. Cont. Nat. Hist. U. S., IV. p. 36G. 18G2. 



Cliondrophone Cham, et Eys. Acta Nova, X. 



From a comparison of the young stages of Nanomia with the known 

 Siphonophora?, I have been induced to extend the Hmits of this sub- 

 order so as to include Phjsaha, forming thus three suborders among 

 Hydroids of the old order of Siphonojihora?, the Diphyje, the Physo- 

 phorse, and the Porpita?. 



Family PHYSALIDiE Brandt. 



Phymlidm Br. ; in Mem. Aead. St. Petcrsb., p. 2.3G. 18.3.5. 

 Physalidce Agass. Cout. Nat. Hist. U. S., IV. p. 3GG. 18G2. 



PHYSALIA Lamk. 



PJii/.ialia Lamk. An. s. Vert., IH. p. 89. Second Edition. 



Ari'thuw Brown. Nat. Hist. Jam. 



Arclhuxa Less. Zooph. Acal., p. .'530. 1843. 



Phjscdia Agass. Cont. Nat. Hist. U. S., IV. pp. 335, 3G6. 



18G2. 



Fig. 351. 



Physalia Arethusa Til. 



PhijsaUa Aretliusa Til. ; in Krusenst. Reise, PI. 23, Figs. 1 -6. 1813. 

 PhysaUa Arcllmsa Olf. ; in Mem. Berl. Acad., PI. 1. 1832. 

 Physalia Arethusa Agass. Cont. Nat. Hist. U. S., IV. jip. 335, 3G7, 



PI. 35. 18G2. 

 Pliysnlio pelaxf/icii Bosc. Hist. Nat. d. Vers, 11. p. 1 68. 

 Physalia auriyera McCr. Gynm. Cliarleston Harbor, p. 74. 



Physalia Arethusa (Fig. 351) is probably carried 

 by the Gulf Stream as far as the Azores. A spe- 

 cies has been described by Lesson as Plnjxalla 

 azorlcum, which may be only the 3'oung of J'hi/- 

 salla Arethusa. (See Voyage de la Coquille, Phite 

 5, Fig. 4.) To facilitate the comparison of the 

 different kinds of individuals found hi communi- 

 ties of this family with those of Nanomia, group.s 



Fig. 351. Physalia Arethusa Til. Figs. 351-354 are copied from 

 Professor Agassiz's Contributions, a, lilunt end of air-sac sujipDrliiig 

 the community ; i. open end of air-sac ; c, crest of air-sac ; )h, bunches 

 of single individuals ; n, tentacle contracted ; (, t, tentacles of the lar- 

 gest kind expanded. 



