34 COSTA RICAN DIPTERA 



below the outer pair and nearer to them than to the post-antennals; surface 

 hairs very short; antennae normal; arista pubescent, longer than frons; 

 palpi normal. Mesopleura bare; scutellum with 2 bristles. Anal segments 

 bristled at the apices. Legs normal; hind tibial setulae about half as long 

 as the diameter of tibia. Wing with costa to middle; first costal division 

 equal to 2+3; angle at apex of vein 1 acute; fork of third vein almost rec- 

 tingular; fourth vein arcuate, finishing in front of wing tip; costal fringe 

 about three times as long as diameter of costa. Length, 1.25 mm. 



Holotype. — Alajuela, September L5, 1909, swept at 3100 feet 

 altitude. Type No. 6049. 



Aphiochaeta exaltata new species 



Female. — Black-brown, shining. Frons slightly pollinose; antennae 

 brownish yellow; palpi yellow. Abdomen black, shining at apex. Legs 

 black-brown, fore legs paler, the tibiae and tarsi yellowish; apices of 

 mid and hind femora yellow, mid tibia yellowish, base and apex of hind tibia 

 yellow, tarsi yellow. Wings clear, veins black-brown. Halteres with yel- 

 low knobs. 



Frons with distinct suture; upper pair of post-antennal bristles widely 

 separated and placed very high on the frons being about in line with mid- 

 way between the central and outer bristles of first row; lower post-antennals 

 very close together and about three-fourths as large as upper pair; central 

 pair of bristles in first row much lower on frons than outer pair and not much 

 furthei* from eye margin than these; surface hairs short; antennae small, 

 third joint round; arista pubescent, distinctly longer than frons; palpi 

 slightly dilated, moderately bristly. Mesopleura bare; scutellum with 2 

 bristles. Abdomen with the segments subequal; the lateral margins of 

 second segment with only weak hair-like bristles. Legs very strong, hind 

 femora dilated ; fore tibia with dorsal setulae ; hind tibial setulae very strong ; 

 hind tibia with double row of setulae. Wing with costa to wing middle, 

 first division slightly shorter than second; angle at apex of first vein acute; 

 fork of third weak rather acute; costal fringe strong and long; fourth vein 

 leaving at slightly before fork, curved at base and ending well in front of 

 wing tip. Length, 1.75 mm. 



Holohjpe. — ^Alajuela, September 8, 1909, swept over brook, 3100 

 feet altitude. Type No. 6050. 



Aphiochaeta lutea Meigen 



1830. Phura lutea Meigen, Syst. Beschr., vi, 219. 



There are four specimens amongst the material before me which 

 evidently belong to this species. The localities are : Rio Siquiares, 

 Turrucares, August 14, 1909, 2200 feet altitude; Rio Surubres, 

 October 21, 1909, 2 specimens by sweeping at 800 feet altitude; 

 and 1 near Tierra Blanca, April 6, 1910. 



