292 PHYSOPHORA. 



Discolabe with four rows of nectophores, is still open. Schneider ('98, p. 126) 

 maintains that the difference is evidence of stages in growth, and instances in sup- 

 port of this view his own observation that "Exemplare mit unten kreuzweise 

 geordneten Glocken kommen aber bei Ph. hydrostatica vor." He also suggests 

 that the arrangement of the bells in four rows from end to end of the nectosome 

 in Haeckel's Discolabe quadrigata and Philippi's P. tetrasticha is to be explained 

 on the assumption that "diese tetrastiche Anordnung gelegentlich an grossen 

 alten Exemplaren auf die ganze Schwimmsaule ubergreift." Philippi's form 

 probably was hydrostatica, with the stem spirally twisted, as Gegenbaur ('53) 

 pointed out. But Haeckel's Discolabe can not be explained thus; and inasmuch 

 as a biserial nectosome is certainly the rule even in large specimens of Physo- 

 phora, and since Discolabe quadrigata has been recorded only once, it is better 

 to retain it as a provisional species until it can be studied again. 



PHYSOPHORA FoRSKAL. 



The union by Chun ('97b) of the various Atlantic and Mediterranean 

 Physophoras was undoubtedly justified, and is generally accepted. Although 

 the genus has long been known from the Pacific and Indian Oceans, from the 

 records by Quoy and Gaimard ('34) and Brandt ('35), the older descriptions were 

 not sufficiently accurate to establish the relationship of their subjects with the 

 Atlantic species. Even Huxley ('59) dared venture no identification of the 

 species of which he gave so accurate an account. So far as I can learn the only 

 recent record of the genus from the Indo-Pacific region is by Lens and Van 

 Riemsdijk (:08), who were unable to separate the "Siboga" specimens from 

 P. hydrostatica, and therefore record them under that name. The better 

 preserved series at my disposal leads to a similar conclusion. I have not been 

 able to compare our specimens from the Pacific with specimens from the 

 Atlantic. But the structure of P. hydrostatica is now so well known, thanks 

 especially to the investigations of Gegenbaur ('60), Glaus ('60, '78), Sars 

 ('77), and later authors, that it is easy to judge the relationship between it 

 and the Pacific form. 



The presence of P. hydrostatica in the Eastern Pacific as well as in the 

 Malaysian region, the Atlantic, and its occurrence in high latitudes in the latter 

 ocean and even within the Arctic Circle (Romer, :02) and off Iceland (Paulsen, 

 :09) shows that it has a distributioja comparable with that of Nausithoe 

 punctata among Medusae. 



