314 Mr. J. E. Col]in*s Contrihiition towards knotvledge of 



of frons comi^ared with width of head as about 22 : 100; frontal 

 stripe about double as wide in front as at narrowest part; frontal 

 bristles numerous (10-11 pairs); long, upcurved bristles on jowls 

 much less numerous than in the male or in obtusa $. Thorax very 

 inconspicuously striped but brownish about middle and on indis- 

 tinct stripes oi- patches, which however vary considerably in colour 

 according to the point of view. Abdomen whitish-grey with a brown 

 central stripe and distinct brownish tessellations which remain more 

 or less visible about base of segments from most points of view. 

 Bristles on hind-margin of last visible segment weak. Legs much 



Detail 



genitalia of //. unilineaia Zett. X 33. 



as in obtiisa 5 except for the more anteroventral, instead of ventral, 

 bristle to middle tibiae. Wings often with the veins faintly clouded 

 with yellowish-brown. 

 Length 6-8 mm. 



Under this species in Zetterstedt's Dipt. Scand. Collec- 

 tion there are four males and three females; two of the 

 males (one with locality label " Kjellby") are H. sponsa; 

 the other two males (one with label " Ernaes " and the other 

 " La])^.") and three females (one with label " Ernaes ") 

 belong to the species described above. In the collection 

 at Stockholm under unilineata there are a pair of obtusa, a 

 male of sponsa, and one male and five females of the species 

 described above ; a pair of these latter bear a label " Zett." 



