LEPTOMEDUS/E — OBELIA. 



241 



The variations of the medusae of Obelia have been made the subject of elaborate study by 

 Agassiz and Woodworth, 1896 (Bulletin Museum Comp. Zool. at Harvard College, vol. 30, 

 p. 121, 9 plates). These authors obtained the medusas in surface-tows made at Newport, 



General Characters of the So-called Species of Obeha — Continued. 



*0. fragiiis Calkins resembles this species, but hydrocaulus is creeping, never erect, and margins of pedicels sinuous. 

 ■{■Distinguished by its numerous tendrils at ends of branches. Probably a variety of 0. geniculata. 

 } Probably a variety of 0. geniculata. 



