Status of Exosphaeromaamplicauda (Stimpson 1857) E.aphrodita (Boone 1923) and description of three new species (Crustacea Isopoda Sphaeromatidae) from the north-eastern Pacific

摘要

Exosphaeroma amplicauda (Stimpson, 1857) from the west coast of North America is reviewed and redescribed and revealed to be a group of closely related species. A neotype is designated and the species redescribed based on the neotype and topotypic specimens. Exosphaeroma amplicauda is known only from the coast of California, at Marin, Sonoma and San Mateo Counties. Exosphaeroma aphrodita (Boone, 1923), type locality La Jolla, California and previously considered nomen dubium is taken out of synonymy and re-validated. A further three species: Exosphaeroma paydenae >sp. n., Exosphaeroma russellhansoni >sp. n., and Exosphaeroma pentcheffi >sp. n. are described herein. Sphaeroma octonctum Richardson, 1899 is placed into junior synonymy with Exosphaeroma amplicauda. A key to the Pacific West Coast Exosphaeroma is provided.