Description of a common stauromedusa on the Pacific Coast of the United States and Canada, new species (Cnidaria: Staurozoa).

"" is the most common staurozoan on the west coast of the United States and Canada. This species was described in the M.S. Thesis by Gellermann (1926) and although that name has been in use nearly continuously since that time, no published description exists. Furthermore, the most popular operative name for this species has varied between several related species names over time, resulting in confusion. Herein, we provide a detailed description and synonymy of n. sp., whose distribution is verified from Unalaska Island in the Aleutians (53.4° N, 166.8° W) in the northwest, to Santa Barbara County, California, just north of Point Conception (34.5° N, 120.5° W), in the south. n. sp. is compared with the twelve other described species of and illustrations of both macroscopic and microscopic anatomy are provided. n. sp. is unique among species of in the arrangement of the bright-white nematocyst spots in its calyx and the pattern of dark stripes running the length of the stalk and up the outside of the calyx.