부산대학교 도서관

Centroptilum infrequensMcDunnough, 1924 was found to be widespread in Canada and was described in detail at the 5th International Ephemeroptera Conference, Marysville, Australia, 1987 (Lowen and Flannagan 1989). At that time, similarities between C. infrequensand published accounts of Pseudocentroptilum pennulatum(Eaton 1870) were noted and it was suggested that these species are conspecific. We have recently compared specimens of C. infrequenswith specimens of P. pennulatumfrom western Europe, and have noted no discernable differences at any life stage. We therefore conclude that Centroptilum infrequensMcDumough, 1924 is a junior synonym of Pseudocentroptilum pennulatum(Eaton) 1870. This is the first record of Pseudocentroptilumin North America and the first record of a holarctic Pseudocentroptilumspecies, as P. pennulatumis also known from the arctic Ural and Pacific Coast regions of the Soviet Union.