SCI AHA. 51 



costal vein little more than one-fourth of the length of the wing ; radial 

 a little more than two-thirds of the length ; cubital simple, ending at a 

 little in front of the tip ; subapical emerging from the cubital before 

 one-third of the length, forked before two-thirds of the length ; sub- 

 anal and anal diverging to the posterior margin ; subanal simple ; axil- 

 lary and subaxillary rudimentary ; humeral veinlet very near the base. 

 Areolets ten the humeral, the subcostal and the radial, which are 

 partly united, the praebrachial, the pobrachial, the cubital, the subapi- 

 cal, one externo-medial, the anal, and the axillary. Posterior margin 

 forming a slight acute angle at a little beyond the length of the humeral 

 areolet from the base. Halteres rather long. Abdomen elongated, 

 nearly linear. Legs slender, of moderate length ; coxse rather large ; 

 tibiae without spines, their spurs rather short. Male. Antennae nearly 

 as long as the body. Abdomen bilobed at the tip. Fern. Antennas 

 not more than half the length of the body. Abdomen attenuated at 

 the tip. 



The larvse of this genus dwell in Boleti, fungi, putrescent galls, 

 and beneath the bark of felled trees, and at the decayed roots of 

 vegetables. The larva of S. vitripennis is exactly like that of 

 MycetophUa fusca, but does not spin a cocoon ; the pupa differs 

 in having two divergent caudal setse, and its head is cleft in front. 

 Synopsis of the species : 



a. Kadial vein extending beyond the fork of the subapical. 

 b. Wings blackish. 



c. Sides of the abdomen luteous. Species 1. 

 c c. Sides of the abdomen black. Species 2. 

 b b. Wings grey. 



c. Legs piceous. Species 3. 

 c c. Legs testaceous. Species 4, 5. 

 b b. Wings nearly limpid. Species 6. 



a a. Radial vein extending to the fork of the subapical. Species 7, 8. 

 a a a. Radial vein not extending to the fork of the subapical. 

 b. Halteres piceous or brown. 

 c. Wings brown. Species 9. 

 c c. Wings grey. Species 10. 

 c c c. Wings limpid, or nearly so. 



d. Subapical and subanal veins dark. Species 11, 12. 

 d d. Subapical and subanal veins whitish. Species 13, 14. 

 b b. Halteres testaceous, with blackish knobs. Species 15, 16. 

 b b b. Halteres testaceous or whitish. 

 c. Wings complete. 



d. Body black or brown. 



e. Subapical and subanal veins blackish. Species 17. 

 e e. Subapical and subanal veins pale. 

 /. Body rather slender. Species 18, 19. 

 //. Body very slender. Species 20. 

 d d. Body tawny. Species 21. 



