KEVISION OF THE TWO-WINGED FLIES OF THE GENUS COELOPA MEIGEN IN NORTH AMERICA By J. M. Aldrich Associate Curator, Division of Insects, United States National Museum The present revision has been prepared as the result of recent correspondence with Mr. J. E. Coilin, of Newmarket, England, who-has furnished information relating to synonomy and has also sup-plied the Museum with determined European specimens; from his data and the specimens it appears that the North American members, of the genus have been misidentified to a large extent. Two species-from the Bering Sea region, formerly considered to be identical with European forms, are here described as new. All the species appear to breed in the kelps, and are found only on seashores where seaweeds of this group are washed up. This limits the distribution of the flies on the Atlantic side to the northern coast, with Rhode Island as the southern terminus, but on the Pacific the kelps extend much farther south, so that one species of the fly is common at least as far south as San Diego, Calif. Genus COELOPA Meigen Coelopa Meigen, Syst. Besehr., vol. 6, 1830, p. 8. — Haliday, Ann, Nat. Hist., vol. 2, 1839, p. 186. — Westwood, Introd. Mod. Classif. Ins., vol. 2, Synops., 1840, p. 144. — Stenhammar, Skaudinaviens Copromyzinae (Kongl. Vetensk. Akad. Handl.) 1853 (1855), p. 317.— Loew, Hon. N. Amer. Dipt., vol. 1, 1862, p. 42. — ScHiNER, Fauna Anstriaca, Diptera, vol. 2, 1864, p. 319. — Cole and LovETT, List Dipt, of Oregon (Proc. Cal. Acad. Sci., ser. 4, vol. 11) 1921, p. 320. — WiLLiSTON, Manual N. Amer. Dipt., ed. 3d., 1908, p. 317. — Malloch, N. Amer. Fauna No. 46, 1928, p. 214, keys to species. Fucomyia Haliday, Ann. Nat. Hist., vol. 2, 1839, p. 186. — Westwood, Introd. Mod. Classif. Ins., vol. 2, Synops., 1840, p. 144. The genotypes of Coelopa and Fucomyia have been remarkably confused, owing to the misidentification of Musca fHgida Fabricius. This was the only species included in Goelopa by Meigen in 1830, but Haliday in 1839 recognized that it was not the true frigida of Fabricius, and gave the name pilipes to Meigen's species, which thus attains the status of genotype and has been so accepted by Mr. Collin, although the matter has not been discussed in print. No. 2808.— Proceedings U. S. National Museum, Vol. 76, Art. 11 61588—29 1
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