Notes on Some Eastern Pacific Species of Phialidium (Leptomedusae)

Abstract

A collection of Phialidium was sent to me by Dr. E. C. Roosen-Runge, University of Washington, Seattle, who wanted my opinion on their specific affinity. They were collected at Friday Harbor in Puget Sound, some few in August 1959, a great number in June 1960. They all belong to one species and agree perfectly with the species which was described by Murbach and Shearer (1903) under the name Phialidium gregarium (A. Agassiz). It is questionable, however, whether the medusa observed and carefully described by Murbach and Shearer really belonged to the same species, which was briefly described by Agassiz as Oceania gregaria.