1918] Revision of the Genus Sciara 321 



flf. The perpendicular distance from the crest of the arc of Mi to that of 

 Rs less than the perpendicular distance from the tip of Rg to Mi. 

 g. Petiole of cubitus less than three-fourths the length of the base 

 of media; costa produced at least two-thirds the distance between 

 the tips of Rs and Mi (Fig. 34). Clasper (Fig. 3), 



3. cylindrica n. sp. 



gg. Petiole of cubitus more than three-fourths the length of the 



base of media; costa not produced two-thirds the distance 



between the tips of Rg and Mi. 



h. Wing wide at base, subcosta exceptionally long and almost 



reaching the costa, base of Rg evanescent; setae or slender 



spines at tip of clasper larger than the setae along the inner 



margin; tip of Rg ends proximad of tip of M2 (Fig. 35). Clasper 



(Fig. 4). (See figures in this paper) 4. congregata Joh. 



hh. Wing normal at base; subcosta normal; base of Rg distinct; 

 setas at apex of clasper not larger than those along its inner 

 margin; tip of Rg ends slightl}^ distad of tip of M2 (Fig. 36). 



Clasper (Fig. 5) 5. psittacus n. sp. 



cc. Ri ends about opposite or distad of the base of the fork of M; species 2.5 mm 

 or more in length, 

 d. Petiole of cubitus over one-half as long as the basal section of M. 



e. Ri ends about opposite the forking of M. (Fig. 221) futilis Joh. 



ee. Ri ends distad of the forking of M. (Fig. 266) ahdita Joh. 



dd. Petiole of cubitus less than one-fourth as long as the basal section of M. 

 e. Humeri, pleura in part and hypopygium (Fig. 103) more or less yellow; 



knob of halteres dark ochrolabis Loew. 



ee. Thorax and aljdomen black. 



f. Clasper with two distinct clusters of stout spines, one apical, the 



other subapical (Fig. 104) sciophila Loew. 



ff. Clasper of different structure. 

 g. Halteres and coxae yellow. 



h. Clasper with a few, about 5 subequal stout spines along the 



inner margin (Fig. 139) hahilis Joh. 



hh. Clasper (Fig. 6) with many, over 12 subequal, rather slender 

 spines along the inner margin. Wing (Fig. 37), 



6. habilis var. 

 gg. Knobs of halteres and coxae fuscous. Wing (Fig. 38). Clasper 



(Fig. 7) 7. globosa n. sp. 



aa. Genus Neosciara. Media and cubitus without setae. 

 b. Large southern species, 6 mm. or more in length; males undescribed. 

 c. Ri ends distad of the base of the fork of M; wings blackish (Fig. 218), 



picea Riibsaamen 



*cc. Ri ends about opposite the base of the fork of M cingulata Riibsaamen 



bb. Medium or small species. 



c. Ri ends distad, or opposite (not more than one-tenth of wing length proxi- 

 mad) of the base of the fork of M, and base of Rg at or proximad of a 

 point midway between the humeral crossvein and the tip of Ri. 

 d. Thorax yellowish to rufous, coxae and femora dull yellow. 



e. Claspers large, triangular, no terminal stout spine. Petiole of cubitus 

 less than one-half as long as the basal section of media (Fig. Ill), 



fulvicanda Felt 



ee. Clasper (Fig. 8) cylindrical, with one stout apical spine. Petiole 



of cubitus more than one-half as long as the basal section of media. 



Wing (Fig. 39) 8. fcilca/a n. sp. 



dd. Thorax dusky. 



e, Rg ends proximad of the tip of Mo; halteres dark. 



f. Clasper with 2 median lobes (Fig. 109); costa produced about one- 

 half way from tip of Rg to Mi tridentata Rubsaamen 



ff. Clasper without median lobes; costa produced distinctlv over half 

 way from tip of Rg to Mi. 

 g. Clasper with 2 or 3 stout apical spines. 



