J. R. MALLOCH 249 



and serva, and the fine hairs surrounding bases of the notopleural 

 bristles are present as in serva. The fore tibia in either sex may 

 have or lack the posterior median bristles. 



I have seen this species from Moscow (type), Julietta, and 

 Kendrick, Idaho; Los Gatos, California; Seattle, Washington 

 and Cache Junction, Utah. 



It occurs in February, and on till ^lay, usually frequenting 

 the flowers of willows. 



Phaonia versicolor Stein 



Phaonia versicolor Stein, Arch, fiir Naturges., abt. A, heft 9, 1918, p. 16, 1920. 



This species, which was described from one female, is unknown 

 to me. The type was obtained by Dr. Aldrich, in JVIarshall Pass, 

 Colorado. It may not be related to the species with which I 

 have associated it in my key, but I accept Stein's comparisons as 

 indicating that it is. 



Length, similar to serva. 



Phaonia basiseta Malloch 



Pliaouiu baaiscta Malloch, Trans. Amer. Ent. Soc, xlvi, p. 133, 1920. 



I have seen no additional material since describing the species, 

 except some more specimens from Waubay, South Dakota, and 

 Alaska. The species may be separated at once from its allies 

 by the presence of the sub-basal bristle on posterodorsal surface 

 of hind tibia. The fore tarsi are as in sei'va, and there are sparse 

 hairs adjacent to bases of both the notopleural bristles. 



Length, 7 mm. 



Localities, Bozeman, Montana; Waubay, South Dakota, and 

 Healy, Alaska, July 6, 1921, (J. M. Aldrich). 



This species is most closely related to the European basalts 

 Zetterstedt, having the same bristling of the legs and the same 

 habitus as in that species. But basalis has the femora and tibiae 

 reddish yellow, and the thorax and abdomen with j-ellowish 

 gray pruinescence, while the abdomen has only a black dorso- 

 central vitta and no lateral checkerings. 



The European species morionella Bezzi has the same color and 

 habitus as basiseta, but the eyes are much more widely separated, 

 the vibrissal angle is very much produced, and there are only 

 three pairs of postsutural dorsocentral bristles on thorax. 



TRANS. AM. ENT. SOC, XLVIII. 



