ART. 25. NEW SPECIES OF COSTA EICAN FLIES ALEXANDER. 3 



This interesting little Dicranoniyia is very distinct from all other 

 species known to the writer. It is named in honor of its collector, 

 Seiior A. Alfarp. 



RHIPIDIA (RHIPIDIA) SUBCOSTAUS. new species. 



General coloration obscure brownish yellow ; mesonotal praescutum 

 with three brown stripes; wings yellowish subhyaline with a heavy 

 brown pattern along the costa; posterior and anal cells strongly 

 brownish; anal angle and wing-tip subhyaline; vein Sc long, basal 

 deflection of Cu^ immediately beyond the fork of M. 



Male. — Length 6.3 mm.; wing 7 mm. 



Eostrum and palpi dark brown. Antennal scape dark brown, the 

 flagellum broken. Eyes contiguous on the dorso-median line, the 

 restricted vertex brown, light gray pruinose. 



Mesonotal praescutum pale testaceous yellow with three brown 

 stripes, the lateral stripes remote from the median stripe ; scutum 

 testaceous, the lobes brown; scutellum brown, paler basally; post- 

 notum pale, conspicuously dark brown medially, narrowly split by 

 a pale median line. Pleura injured by insect pests. Halteres dark 

 brown, the base of the stem pale, the knobs large. Legs with the 

 coxae and trochanters obscure yellow ; remainder of the legs broken. 

 Wings yellowish subhj'^aline with a very heavy brown pattern; a 

 series of costal blotches, arranged as follows: At origin of wing; 

 midlength of cell So; origin of Rs; tip of Sc; stigma and in the end 

 of cell 2nd E-^ ; the pale interspaces are very restricted ; a brown 

 wash includes most of cell il/, excepting a blotch near the outer end; 

 cell ^3 except three blotches of the ground color ; most of the posterior 

 and anal cells excepting a large area in cell 1st A at the tip of vein 

 £nd A and the conspicuous anal angle of the wing which are sub- 

 hyaline ; wing tip in cells 2nd i?i, R^, R^, and 2nd M^_ broadly and 

 conspicuouslj'' pale ; broad darker brown seams along the cord and 

 outer end of cell 1st M^\ veins brown, more yellowish in the sub- 

 hyaline areas. Venation : Sc long, Sc-^^ extending to about opposite 

 two-thirds the length of Rs; Sc^ at the tip of Scj^ and about twice 

 as long as Sc^^ alone ; Rs long, gently arcuated at origin ; inner end 

 of the small cell 1st M^ gently arcuated, lying proximad of the inner 

 end of cell ^5; m a little shorter than the outer deflection of J/^ ; 

 basal deflection of Cu^ just beyond the fork of il/, about equal to 

 Cu2\ 2nd Anol vein bisinuous; longitudinal veins beyond the level 

 of the origin of Rs with long macrotrichiae. 



Abdominal tergites brown, the basal segments and hypopygium 

 more yellowish; sternites obscure yellow. Hypopygium with the 

 dorsal appendage a conspicuous hook, only slightly curved, the apex 

 produced into a chitinized point. 



Hahitat. — Costa Rica. 



3136— 22— Proc.N.M.Vol.60 46 



