Mr. J. W. Fewkes on Deep-sea Medasce. 249 



animals presents fewer difficulties in studying the questions 

 which we have stated than this. 



It was with the impetus of a new enthusiasm for the study 

 of these questions that t undertook, by the advice of Prof. 

 Verrill, the examination of the rich collections of deep-sea 

 Medusae made in the Gulf-stream by the ' Albatross.' It 

 seemed to me that the examination revealed much of general 

 scientific interest. 



I shall not consider in this discussion the Hydroida, as the 

 members of this group are for the most part attached to the 

 ground, and the problems connected with them are the same 

 as those which pertain to all deep-sea animals attached to or 

 partially living on the ocean-bed. We shall also pass by in 

 silence the Ctenophora, no genus of which has yet been 

 ascribed to the deep sea. I propose to consider a few of those 

 jelly-fishes which are known as the-4cras^ec?a, and incidentally 

 the Siphonojyhora. 



The history of the study of the deep-sea Medusse belonging 

 to these divisions is a very brief one. In many of the mono- 

 graphs on these groups we have isolated mentions of Medusse 

 which are ascribed to the deep sea. The jelly-fishes thus 

 mentioned were commonly washed into shallow water by ocean- 

 currents, by storms, or unusual events in the ocean, and the 

 depths at which they were supposed to live could only be 

 conjectural. The specimens themselves were, for the most 

 part, in a mutilated condition. 



The first and only paper on the Siplionophora of the deep 

 sea is by Prof. Studer *, who describes new species and genera 

 of these animals which were found twisted on ropes and wires 

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

 closely related to a genus called B/iizop/zysa, which is itself 

 allied to a Medusa called P/ii/salia, or the " Portuguese 

 man-of-war," wdiich 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 f by Prof. E. Hasckel on a collection made by 

 H.M.S. ' Challenger.' No one has done more than he to 

 elucidate the structure of the jelly-fishes, and he stands without 

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

 members of the group. This work of Hgeckel is, up to the 



* * Zeitsclirift fiir wissenscliaftliclie Zoologie,' vol. xxi. 



t " Keport on the Deep-Sea Medusae dredged by H.M.S. ' Cliallenger ' 

 during the years 1873-76." Eeport on the Scientific Results of the 

 Voyage of H.M.S. ' Challenger ' during the years 1873-76, vol. iv. no. ii. 



