THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SIXTH SERIES.] 



No. 5. MAY 1 



XXXVIII. — On a new Physophore, Plceophysa, and its Re- 

 lationsliips to other Siphonophores. By J. Walter 

 Fewkes*. 



[Plate XVIL] 



One of the most interesting Sipbonopliores collected by the 

 United -States Fish-Commission steamer ' Albatross ' in the 

 Gulf- stream is a new genus, Fl(£ophysa^ which has most 

 interesting morphological atfinities with known genera of these 

 animals. This Medusa, notwithstanding its very interesting- 

 relationships, has never been described. The structure of the 

 genus is so exceptional and its anatomy throws so much light 

 on the morphology of other little-known Physophores that a 

 description of it seems worthy of special publication. 



Plceopiliysa was picked out of a bottle of "surface skim- 

 mings " obtained by the ' Albatross ' during her cruise of 

 1886 f. Two fine specimens were found, both of which exhibit 

 the characteristic features here described and fio-ured. 



* Communicated by the Author, by permission of G. Brown Goode, 

 U.S. Fish Commissioner. 



t The bottle in which Plceophysa was found had not been examined 

 when my Reports on the Meduste collected by the ' Albatross ' were 

 written. 



Ann. & Mag. N. Hist. Ser. 6. Fol i. 22 



