8 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



Chimarra (Curgia) wilsoni, new species 



Figures 25, 26 



This is another member of the C. barrettae group and is probably 

 closest to C. barrettae itself, from which it differs in possessing a 

 pointed tenth tergum and a mesal point on the clasper. 



Adult. Length of forewing 7.5 mm. Color brown, legs and 

 antennae slightly paler, head with hairs golden, wings with golden 

 spots intermingled with brown. Male genitalia: Eighth tergum 

 simple, posterior margin slightly projecting, but otherwise unmod- 

 ified. Ventromesal process of ninth segment terete, longer than 

 broad. Tenth tergum hoodlike, developed into an elongate dorso- 

 mesal point. Clasper almost quadrate in lateral aspect, apicoventral 

 angle slightly developed, and bearing a strong dorsomesal spine. 

 Aedeagus tubular, slightly curved, with a short spine (others broken 

 off?) and a pair of intertwined C-shaped sclerites. 



Holotype, male: Costa Rica, Las Cruces near San Vito, Mar. 19-20, 

 1965, Duckworth. 



I take pleasure in dedicating this species to Robert Wilson, on 

 whose property the species was collected and who was very helpful 

 to Donald and Sandra Duckworth during their stay in southern 

 Costa Rica. 



PSYCHOMYIIDAE 



Polyplectropus macrostylus, new species 



Figures 27, 28 



This species is distantly related to P. thilus (Denning), from which 

 it differs in the larger outer lobe of the cercus and the smaller baso- 

 lateral lobe of the clasper. 



Adult. Length of forewing 6 mm. Brown, antennae annulate, 

 forewing with many spots of golden hair. Male genitalia: Ninth 

 segment almost circular in lateral aspect. Tenth segment mem- 

 branous. Cercus divided into three parts: a thin outer plate slightly 

 longer than broad; a short, broad inner lobe; and a long slender style 

 first directed anteriorly, then curving posteriad. Clasper with an 

 upright basolateral lobe about as high as long, and a long, flat ventral 

 lobe with a short apicodorsal point. Aedeagus short, with ventral 

 lip greatly prolonged, and a stout internal Y-shaped sclerite. 



Holotype, male: Costa Rica, Golfito, Apr. 25-28, 1965, Duckworth. 



Polycentropus costaricensis, new species 



Figures 29-32 



This species is perhaps closest to P. picana Ross, from which it 

 differs greatly in the shape of the claspers and cerci. 



