326 Annals Entomological Society of America [Vol. XI, 



kk. Costa produced over two-thirds from Rg to Ml . 



1. Clasper with two apical teeth (Fig. 121). Petiole of 

 cubitus about three-fourths as long as basal section 

 of M. Hind tarsus shorter than the tibia. 



sp.-SS Joh. 

 11. Clasper with a median process (Fig. 122). Petiole of 

 the cubitus about half as long as the basal section of 

 M. (Fig. 242). Hind tarsus and tibia subequal. 



neglecta Joh. 

 ii. Rs ends distad of .85 of wing length. 



j. Clasper with one prominent terminal or subterminal spine 

 or tooth, or if several teeth are present, one is conspicu- 

 ously larger than the others. 

 k. Costa produced about one-half way from Rg to Mi. 



1. Halteres bright yellow. Claspers (Fig. 125). Wing 

 (Fig. 243). Rs ends distad of the tip of M2. 



{^nigricans Joh.) johannseni End. 

 11. Halteres fuscous. Rg ends opposite or proximad of the 

 tip of M2. 

 m. Rs ends about opposite the tip of M2; Wing (Fig. 217). 



Mesonotum highly polished achiosa Joh. 



mm. Rg ends considerably proximad of the tip of M2 

 (Fig. 56). Mesonotum shiny. Clasper (Fig. 25). 



25. hamata n. sp. 

 kk. Costa produced over half way from Rg to Mi. 



1. Costa produced over three-fourths way from Rg to Mi 

 (Fig. 244). Halteres yellow. Claspers (Fig. 126). 



S. sp. S7 Joh. 

 11. Costa produced less than .7 from Rg to Mi. 



m. Ri ends over one-fifth of wing length proximad of 

 the forking of the media (Fig. 245). Halteres 



dark. Clasper (Fig. 127) dolens Joh. 



mm. Ri ends considerably less than one-fifth of wing 

 length proximad of the forking of M. 

 n. Apex or near the apex of clasper with a number of 

 spines of which one is somewhat larger or stouter 

 than the others. 

 o. Halteres yellow. Clasper (Fig. 132). 



dibit a Joh. 

 00. Halteres dark. Clasper (Fig. 140). 



diluta Joh. var. a. 



nn. Spine of apex of cla.sper distinctly differentiated 



from the apical setse or from those near the apex. 



o. Halteres yellow. Clasper with no subapical 



spines differentiated from the setae of the 



clasper. 



p. Costa produced less than five-eighths of the distance 



from Rs to Mi. 



q. Hind tibia a little shorter than the tarsus. 



Wing (Fig. 246) varians Joh. 



qq. Hind tibia and tarsus subequal in length. 



varians, var. a. 

 pp. Costa produced over two-thirds of distance 



from Rg to Mi varians, var. b. 



00. Knobs of halteres fuscous. 



p. Clasper (Fig. 26) with several long slender 

 subapical spines, a little longer than the 

 stout apical spine. The distance from the 

 tip of Ri to the point on the costa opposite 

 the forking of M is greater than the distance 

 between the tips of Mi and M2 (Fig. 57). 



26. felti n. sp. 



