344 CATALOGUE OF NORTH AMERICAN DIPTERA. 



subopacus LoEW, Cent., vi, 74. — D. C. 



WiLLiSTON, Biologia, Dipt., iii, 88, oc. and note. — Guerrero, Mex. 

 Hough, Proc. Boston Soc. Nat. Hist., xxix, 79, type redesc. ' 

 Montreal — Chagnon. 

 subvirescens Loevv, Cent., x, 58.- — Texas. 



? Walker, Trans. Ent. Soc, iv, 150 (translatus) . — U. S. [Hough, with 



a ?] 

 WiLLiSTON, Dipt, of Death Val. Exped., 255 (aridus). — Argus Mt., Cal. 



[Hgh.] 

 Hough, Boston Soc. Nat. Hist., xxix, 84. — New Bedford, Mass. ; Tifton, 



Ga. ; Opelonsas, La. 

 Montreal — Chagnon. 

 willistonii Kertesz, Wien. Ent. Zeit., xix, 1900, 244, change of name. 



WiLLiSTON, Biologia, Dipt, iii, 88 (aculcatus, preoc.) ; Trans. Ent. Soc. 

 Lond., 1896, 351 (id.). — Tabasco, Mex.; St. Vincent, W. I. 

 xanthopodus Williston, Biologia, Dipt., iii, 87. — Guerrero, Mex. 



VERRALLIA. 



MiK, Wien. Ent. Zeit., xviii, 137, 1899. 



Becker, Berl. Ent. Zeitsch., xlii, 1897, 93 (Prothecus Rond.). 



Note. — According to Mik, loc. cit., Rondani made an error of identi- 

 fication, and the species he named as the type is not auctus, but has an 

 acuminate third antenna! joint. This antennal character is mentioned in 

 the definition, hence Prothecus could not be used for the present group, 

 in which the lack of a point on the third antennal joint is one of the 

 principal characteristics. 

 opaca Williston, Trans. Amer. Ent. Soc, xiii, 295 (Pipunculns). — Wash. 



Hough, Proc. Boston Soc. Nat. Hist, xxix, yy, refers to Prothecus, in 



Becker's sense. 

 Kertesz, Wien. Ent. Zeitung, xix, 244, refers to Vcrrallia. 



SYRPHID^. 



Williston, Synop. N. A. Syrphidae. Bulletin of The United States National 

 Museum, No. 31. Washington, 1886, xxx and 335 pages, with 12 plates. 

 The largest and most complete family monograph yet published on North 

 American Diptera. 



Verrall, British Flies. Syrphidse, etc. Gurney and Jackson, London, 1901. 

 690 pages, portrait and many excellent text figures. Includes also in an 

 appendix of 121 pages a full catalogue and bibliography of the British rep- 

 resentatives of the three families described, which are the Platypezidse, Pipun- 

 culidse and Syrphidse. This massive volume is an encyclopedia on the three 

 families indispensable to the advanced worker. Many of the British species 

 and most of the genera occur also in America. 



Chagnon, G., £tudes Preliminaires sur les Syrphides de la Province de Que- 

 bec. Chicotini, Quebec, 1901, 75 pages. Originally published in parts in " Le 

 Naturaliste Canadien," 1901. I quote the separate edition. It is a convenient 

 and useful compilation on the commoner species of that region. 



MICRODON. 



Meigen, Illig. Mag., 11, 275, 1803; Syst. Beschr., in, 162, 1822. 

 Latreille, Hist Nat Crust et Ins., xiv, 358; 1805 {Aphritis). 



