16 



PKOCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 78 



casionally there are a few scattered fine hairs below the lowest 

 frontal bristles. 



Thorax and scutellum black, gray pollinose, usually subshining; 

 thoracic chaetotaxy as in frenchii. Abdomen black, gray pollinose, 

 the pollen var3dng greatly in density and pattern ; anal segment usu- 

 ally concolorous with the remainder of abdomen, but frequently 

 more thickly gray pollinose, never golden. First three segments of 

 abdomen with marginal macrochaetae, the fourth wholly bristly, 

 excepting the extreme base. Abdominal hairs often suberect along 

 the dorsum. 



Mid tibiae with one strong and one weak or, more rarely, with 

 two strong bristles nearly equal in strength, on the outer front side. 



(/#'• 



Figures 7 and 8. — Achaetonedra samiab^ new species, 

 male genitalia. 7, from behind ; 8, side view 



As in frenchii^ there are also two hind bristles and a strong inner 

 one present. Hind tibiae evenly ciliate with one longer bristle. 

 Wings hyaline with one or two bristles at base of third vein. 



Genitalia (figs. 7, 8) much larger than those of the typical frenchii. 

 Forceps viewed from behind, at widest part, more than one-third as 

 wide as long. Inner forceps black, fused for about one-half their 

 length and furnished with a well-defined keel; viewed in profile 

 nearly straight and tapering to fine points, their length nearly three- 

 fourths that of length of fourth segment ; outer forceps black or red- 

 dish, broad at base and moderately tapering to rounded points. 



Length, 7-9 mm. 



The species is readily distinguished from all others of the genus 

 by its puparium (fig. 14), which is usually weak, light brown in 

 color, with the posterior spiracles always located in a depression on 



