439 



Hypopygium similar to that of decorus (PI. XXXIII, Fig. ii) except 

 that the superior process is comparatively longer, more slender, and 

 more distinctly curved, and the apical portion of the lateral arm is not 

 constricted at apex. Fore tarsi with long hairs, basal joint about one 

 third longer than fore tibiae (92:68). Venation similar to that of 

 matiirus. 



female. — Agrees with the male in color. The basal joint of fore 

 tarsus is slightly longer in comparison with the tibia than in the male, 

 and the long tarsal hairs are absent. Otherwise as the male. 



Length, 7-8 mm. 



Type locality, Dubois, 111., April 24, 19 14 (C. A. Hart and J. R. 

 Malloch). Several specimens taken at light; the orhers swept from 

 vegetation on banks of streams. 



This species differs from hyperhoreiis Staeger in having the abdo- 

 men with very conspicuous yellow bands and the legs yellowish instead 

 of black. 



20. Chiroxomus claripexnis, n. sp. 



Male. — Black, slightly shining. Head black, antennal plumes fus- 

 cous. Mesonotum slightly pruinescent, most distinctly on spaces be- 

 tween the vittae ; scutellum sometimes brownish. Abdomen black or 

 blackish brown, hypopygium yellowish. Legs brown, tibise and basal 

 half of tarsi yellowish. Wings clear, veins entirely yellowish. Halte- 

 res yellow, the knobs sometimes brownish. Hairs on body and legs 

 yellowish. 



Differs from the preceding species in being much shorter, 4.5-5 

 mm., in having the basal joint of the fore tarsi one fourth longer than 

 the fore tibiae (45 : 36), and the hypopygium much more slender, with 

 the superior and inferior processes very short (PI. XXXVI, Fig. 4). 



Female. — Differs from the male in having the ground color of the 

 thorax brownish yellow. 



Length, 3.5-4 mm. 



Type locality, South Haven, Mich., July 14-15, 19 14 (C. A. 

 Hart). One specimen taken at light; the others on shore of Lake 

 Michigan. 



A female taken at Grand Tower, III, April 21, 19 14, on the bank 

 of the Mississippi River by IMr. Hart and the writer differs from the 

 type in having the halteres dark brown, the pale posterior margins of 

 the abdominal segments very narrow, the last joint of fore tarsi 

 shorter in comparison with the fourth (8:16 as against 7:11) and the 

 cubitus forking more distinctly beyond the cross vein. 



This specimen may represent a distinct species. 



