VARIATIONS AMONG SCYPHOMEDUSiE.^ 



BY 



CHAS. W. HARGITT. 

 With i Plate and 17 Figures in the Text. 



During the course of a study of variations among Hydrome- 

 dusae in 1901 the present writer became interested in facts of a 

 similar sort which came under observation incidentally as certain 

 specimens of various Scyphomedusae were observed. Further- 

 more, during the course of extended studies in the development 

 of Cyanea additional facts of a very interesting kind were observed. 

 Still later in connection with experiments on regeneration in 

 Rhizostoma pulmo ('04) other facts bearing more or less directly 

 upon the same general problem were accumulated. 



It is the purpose of the present paper to present a synopsis of 

 the facts and to attempt a statistical exhibit of certain features of 

 the variations observed, as well as an analysis of the data with a 

 view to determine something of their bearings on the general 

 problem of adaptation. 



MATERIAL. 



Most of the material was obtained at Woods Hole during the 

 summers of 1901, 1902, 1905. Most of the ephyrae were obtained 

 in April and May 1902, and in March 1904. The adults were 

 collected by the writer at various times during these years in part, 

 and in part by Mr. Vinal N. Edwards, collector for the laboratory 

 of the United States Fish Commission, for whose kindness in 

 turning it over to me for investigation it is a pleasure to acknowl- 

 edge my grateful obligations. I was also permitted to examine 

 a collection of about two hundred specimens of Aurelia collected 

 by Mr. Geo. M. Gray, curator of the Marine Biological Labora- 

 tory supply department, for which courtesy my thanks are due. 



The material was preserved for the most part in 5 per cent 

 formalin. That of my own collecting was preserved in formalin 



'Contributions from the Zoological Laboratory, Syracuse University. 



