THE mycetophilid.'T; of north America. 261 



19. Platyura subterminalis Say. 

 1829. subtermUialis, Say. Joum. Ac. Nat. Sc. Phila. IV. 152. 



J\lale and female. Length 3^- to 4 mm. Body entirely pale 

 honey yellow; antenna; excepting the two basal joints, fuscous; 

 ocelli with a small black areola; thorax immaculate; tergum a 

 little more dusky than the thorax. Tibiae and tarsi dusky. 

 Wings with a slight yellowish tinge, a blackish subterminal 

 band, occupying on the costal margin all the space between R2+3 

 and R4+:; and extending to the posterior margin; R2+3 is perpen- 

 dicular to the costa. 



In two male specimens from Ithaca, N. Y., the hypopygium 

 is as shown in figure 104; the fore metatarsus is about 1.4 

 times, the second fore tarsal joint 7-8 times the fore tibia in 

 length ; the subcosta ends proximad of the base of" the radial 

 sector; the subcostal crossvein is situated proximad of the mid 

 distance of humeral crossvein and tip of the subcosta; R2+3 is 

 perpendicular to R1+5; the petiole of the media is less than half 

 as long as the coalesced part; the anal vein does not reach the 

 margin. 



Var ncxilis n. var. Differs from the typical form in having 

 R2+3 oblique to R-iH-;;; the coalesced part of the media and the 

 petiole subequal and a slight difference in the hypopygium (fig. 

 107). One specimen from Polk Co., ^^'isconsin. 



20. Platyura dihita Loew. 

 1869. diliita, Loew. Berl. Ent. Zeitschr. XIII. 134. 



J\Iale and female. Length 5 mm. Luteous. Antenna; short, 

 fuscous or subfuscous. The immediate bases of the abdominal 

 tergites sometimes fuscous ; the last visible segment and the 

 hypopygium of the male fuscous. Legs pale, tarsi dusky. 

 Wings yellowish, with a short, dilute, subapical fascia; R:+3 

 short, oblique. Halteres yellow. Recorded from D., C. 



I have seen specimens from New York, North Carolina, \\'is- 

 consin and Vermont. The hypopygium is shown in figure 98. 

 The fore metatarsus is about 1-6 longer, the second fore tarsal 

 joint about 1-6 shorter than the tibia. The subcosta ends in 

 the costa proximad of the base of the radial sector ; the sub- 

 costal crossvein is slightly proximad of the midpoint between 

 the humeral crossvein and the tip of the subcosta; R:+3 oblique; 



