334 



Illinois localities : Pulaski, Algonquin, Monticello. and Urbana. 

 Taken on dates ranging from the end of June to the end of August. 

 Early stages and habits unknown. 



3. JOHANNSENOMYIA ARGENTATA Loew 



Cei'atopogon argentatvs Loew, Berl. Ent. Zeitsehr., 1861, p. 310, sp. 5. 

 J ohannseniella argenUiia (Loew) Malloeh, Bull. III. State Lab. Nat. Hist., Vol. 

 10, p. 226. 



Female. — Black, shining. Head yellow, apices of the short joints 

 of flagellum of antennae and the whole of the apical five joints brown. 

 Abdomen black, the surface obscured by dense silvery pruinescence. 

 Legs yellow, blackened on mid and hind coxse, on middle of hind fem- 

 ora and their extreme apices, on basal half of hind tibiae, also apical 

 three joints of all tarsi. Wings with a slight infuscation on cross vein, 

 along anterior branch of media, and on the cells between radius and 

 costa. Halteres black. 



Eyes separated by a narrow line ; antenna reaching to about middle 

 of abdomen. Mesonotum with the disc covered with short closely 

 placed pale hairs, lateral view of anterior half as in Figure 5, Plate 

 XXIII. Abdomen slightly spatulate. Legs slender, noticeably elon- 

 gated; basal joint of hind tarsus longer than the remaining joints to- 

 gether ; fifth tarsal joint on all legs v^^ith a row of 6-7 long bristles on 

 each side of ventral surface extending from base somewhat beyond the 

 middle ; inner claw of each tarsus about a fourth as long as the outer. 

 Third vein to about seven eighths of the wing-length ; first vein about a 

 third the length of third ; media forking distinctly in front of cross 

 vein; cubitus forking below the base of posterior fork of media. 



Length, 3.5-4.5 mm. 



Illinois localities: Pike, May 26, 1906; Monticello, June; Lilly, 

 June 1 1 ; Mt. Carmel, June 30 ; Algonquin, June and July ; LTrbana and 

 Havana, July; and Centerville, August 16. 



It is strange that out of thirty-eight specimens in the collection 

 here there should be no males. The females undoubtedly do predom- 

 inate in Ceratogoponiucc, but this is an exceptional instance. Prof. J. 

 M. Aldrich has taken numerous females of this species at Lafayette, 

 Ind., but no males. By an unfortunate slip this species was not de- 

 scribed in my revision of the genus published in Article IV of this 

 volume. 



Originally described from Washington, D. C. 



Early stages and habits of adults unknown. The male is unde- 

 scribed. 



