GEOGRAPHICAL DISTRIBUTION. 377 



than by rapid reproduction in regions of favorable temperature. The failure 

 of Muggiaea to penetrate bej'ond the Isle of Wight in the English Channel can 

 not be due to temperature, because by June the surface throughout the channel 

 is 57° or over. Nor is there any evidence that it is due to the complex currents 

 in this region and in the North Sea. As pointed out below, (p. 381) sahnity 

 may be the active factor here. 



Bathymetric Range. 



The "Albatross" did not obtain any Siphonophores in closing-nets, although 

 a good many Medusae were taken in such hauls (Bigelow, :09a). The only 

 previous records of the present group from closing-nets, so far as I can learn, 

 are the following : — 



1. Cuboides vitreus, Guinea current, 1,000-1,200 M: " Plankton "; Chun ('97b). 



2. Diphyes appendiculata, Mediterranean, surface down to about 750 fathoms 

 (1,300 M); most abundant at 80-100 M (Chun, '87); 60° 2' N., 22° 7' W., 

 800-1,000 M; "Plankton"; (Chun, '97b, p. 110); Sargasso Sea, 31° 5' N., 

 5° 1' W., 900-1,100 M; "Plankton"; (Chun, '97b, p. 110); 14° 19' N., 27° 

 13' W. 300-350 M, and 1,000 M; "Monaco"; (Bedot, : 04, p. 26, 27); 

 Bay of Biscay, four stations 200-100 fathoms, one station 500-400 fathoms, 

 "Research" (Bigelow, : lib, p. 345). 



3. Diphyes ardica, various depths from the surface down to 800 M; "Nansen" 

 closing-net. (Damas and Koefoed, :07.) I may point out that these 

 deep-sea records are unreliable, because Paulsen (:09) has proved that this 

 type of closing-net often fishes while being lowered. 



4. Chuniphyes multidentata, Bay of Biscay, three Stations 1,250-1,000 fathoms 

 two Stations 1,500-750 fathoms, one Station 2,000-1,000 fathoms (Bigelow, 

 :11b, p. 348). 



5. Rosacea plicata, Bay of Biscay, two Stations 200-300 fathoms (Bigelow, 

 lib, p. 342). 



6. Hippopodius hippopus, larvae, Bay of Biscay, one Station 150-50 fathoms 

 (Bigelow, :11b, p. 350). 



7. Vogtia spinosa, Baj^ of Biscay, one Station 250-150 fathoms (Bigelow, 

 :10b, p. 351). 



8. Apolemia uvaria, Bay of Naples, one Station, 600 M (Chun, '87, p. 13). 



9. Nedalia loligo, 3° 6' S., 33° 2' W., 800-600 M; "Plankton"; (Chun, '97b). 

 And unidentifiable Bathyphysinae from 2,300 M (Chierchia, '85). 



All the other data on the vertical occurrence of Siphonophores consists of 



