J. W. Fewkes — Deep-Sea Medusce. 169 



used in deep-sea dredging and sounding. All of these are 

 closely related to a genus called Hhizophysa, which is itself 

 allied to a medusa called JPhysalia, or the " Portuguese-man- 

 of-war," which habitually floats on the surface of the ocean. 



The most important work which we have on the Acraspeda 

 (the ordinary jelly-fishes found in shallow waters), of the deep- 

 seas, is a report * by Prof. E. Hseckel on a collection made by 

 H. M. S. "Challenger." ISTo one has done more than he to eluci- 

 date the structure of the jelly-fishes, and he stands without an 

 equal in his contributions to a knowledge of the deep-sea mem- 

 bers of the group. This work of Hseckel is, up to the present, 

 the greatest contribution of any naturalist to the study of the 

 medusan representatives of the deep-sea fauna. 



If space permitted, one or two other smaller contributions 

 might be mentioned, but these two works are the most important 

 additions to our knowledge of the cleep-sea Acraspeda and 

 Siphon ophora. 



We have no complete account of the deep-sea jelly-fishes 

 of the G-ulf Stream. That great body of water, which sweeps 

 along our coast from the straits of Florida, northward, bears a 

 nomadic life, of the wealth of which no one has yet a just 

 conception. Those who have studied the stream in all latitudes 

 have spoken of this fact, and one needs but lower a drag net 

 in its waters for a few minutes to become convinced of its 

 truth. The surface of the Gulf Stream has been but partially 

 explored, the inhabitants of its depths, except on the very bed, 

 are unknown. 



The means which have been used for the collecting of ani- 

 mals from intermediate depths are not all that could be wished 

 for. There is a call for greater refinement in this kind of col- 

 lecting. A common way of obtaining this life is as follows. 

 The dredge, trawl or drag-net drawn up from a great depth is 

 found to bring with it a medusa. That medusa is recorded 

 from the depth of the trawl. What then is the possibility that 

 it entered the dredge on the passage up through the water ? I 

 think every one will acknowledge that the possibility is very 

 great, and that the medusa may or may not have come from 

 the deep-sea. A drag-net attached to a dredge-rope or wire is 

 sometimes lowered to a certain depth and then drawn up. 

 Here also we may ask how is it known that the medusa found 

 in the net entered it at the recorded depth ? A Siphonophore 

 clinging to a wire rope used in sounding or dredging may or 

 may not, as shown by A. Agassiz, have become twisted upon it 

 at the depth at which the animal appears to be found when 



* Report on the Deep-Sea Medusae dredged by H. M. S. "Challenger" during 

 the years 1873-76. Report on the Scientific Results of the voyage of H. M. S. 

 Challenger during the years 1873-76, vol. iv, No. II. 



