32 COSTA RICAN DIPTERA 



but not strong. Wings with costa to middle; first division subequal with 

 second, angle at apex of first vein slightly obtuse; angle at fork of third 

 obtuse; third section of costa about one-third as long as second; fourth vein 

 as in flavopleura; costal fringe very long, about 6 times as long as costal 

 diameter; only about 7 bristles from end of vein 1 to fork. Length, 1.5 mm. 



Holotype. — Cartago, October 10, 1909, sweeping over mud. 

 Type No. 6045. 



Aphiochaeta alajuelensis new species 



Male. — Almost identical in coloration with flavopleura, the halteres only 

 being rather paler in color. 



Frons with distinct central furrow; lower pair of post-antennal bristles 

 very small, upper pair strong; center pair of bristles in first row incurved, 

 situated very close to outer pair and comparatively far separated from the 

 post-antennals ; surface hairs short and numerous; antennae of good size, 

 third joint slightly pointed; arista shortly pubescent, its length slightly 

 more than equal to that of frons; palpi larger than third antennal joint, 

 strongly bristled. Abdomen tapering; surface with pale hairs; hypopygium 

 of moderate size; anal protuberance normal, yellow; ventral organs protrud- 

 ing, pale yellow. Fore tarsus normal; hind tibial setulae distinct but weak. 

 Wing with costa to middle; first division slightly longer than second, angle 

 at apex of vein 1 acute; angle at fork obtuse; fourth vein as in latimanus; 

 costal fringe long, about equal in length to four times the costal diameter, 

 5-7 bristles from end of vein 1 to fork. Length, 1.5 mm. 



Holotype. — d", Alajuela, September 15, 1909, swept, 3100 feet 

 altitude. Tj^je No. 6046. 



Paratypes. — 1 male same locality as type, swept over l^rook, 

 September 8, 1909; one female, Turrucares, December 22, 1909, 

 swept over mud. 



Aphiochaeta seticauda new species 



Male. — Black-brown, subshining. Frons almost black, the surface pol- 

 linose. Antennae brownish yellow; palpi yellow. Pleura yellow, upper 

 j)ortions brownish. Abdomen opaque, posterior margins narrowly yellow; 

 anal protuberance clear yellow. Legs yellow, apices of hind femora black. 

 Wings clear, veins j^ellowish. Halteres with brown stalk and lemon yellow 

 knob. 



Frons with very distinct central furrow; only 1 pair of distinct post- 

 antennals present; central pair of bristles in first row situated well below 

 level of outer pair and much nearer to center of frons ; outer pair not very 

 close to eye margin ; surface hairs very short ; antennae large, about ^ as large 

 as eye, third joint oval, darkened above; arista about 1§ times as long as 

 frons, indistinctly pubescent; palpi smaller than antenna, moderately brist- 

 ly. Mesopleura bare; scutellum with 2 bristles. Abdomen broad at base, 

 tapering posteriorly; second segment elongated, 3-4 distinct bristles on lat- 



