154 INSECUTOR INSCITIit MENSTRUUS 



width. Buttocks of anal segment pronounced, the emargination especially 

 distinct. Abdomen without discal macrochaetae save one or two short 

 pairs on second segment emd the buttocks-bunches which cover less than 

 half the length of anal segment. Claws of male about as long as last 

 tarsal joint. 



Reproductive habit, probably leaf-larviposition of colored maggots. 



Type, Quadratosoma rufum, new species. 



Quadratosoma rufum, new species. 



Length of body, 12 to 14 mm. ; same to end of abdominal spines, 

 13.5 to 15.5 mm.; of wing, 12.5 to 13.5 mm.; of proboscis beyond 

 geniculation, 4.75 to 5.25 mm. Two males, Uruhuasi Bridge, about 

 6,500 feet, February 3 and 15, 1910, on flowers of Baccharis sp. 



Head pale yellowish, rather thinly silvery pollinose, the epistoma espe- 

 ciaJly shining ; parafrontals obscure greenish-brown, frontalia light velvety- 

 brown, lunula and first two antennal joints shining brown, third antennal 

 joint and arista soft brown. Ocellar area, upper occipital area, and para- 

 frontals old-gold pollinose. Occipital pile brassy-gray, parafacial and 

 parafrontal pile black. Thorax thinly pale golden pollinose, leaving four 

 narrow vittae of the usual pattern. Scutellum pale yellowish-brown in 

 ground color, with same pollen. Abdomen wholly rufous or pale red ; 

 with a very faint pollen in patches in oblique lights both above and 

 below, not apparent at all in direct view. Pile of abdomen thin and 

 delicate. Legs wholly concolorous with abdomen. Wings wholly and 

 evenly infuscate. Tegulae with about same infuscation as wings, margins 

 narrowly yellowish. 



Melanepalpus, new genus. 



General characters of Epalpus. Description is of both sexes. Pro- 

 boscis extended a little longer than head-height. Second aristal joint 

 more or less elongate. Female front at vertex a little more than eye- 

 width, that of male about two-thirds eye-width. Third antennd joint of 

 female about one and one-fourth times the elongate second joint, that of 

 male fully one and one-half times second joint. 



Two to three sternopleural, two to four postsutural bristles ; none to 

 four postacrostichal, in latter case the two anterior ones weak ; and none 

 to three preacrostichal, in latter case the hind one strongest. Abdominal 

 macrochaetae practically same as in Quadratosoma and Eulasiopalpus. 

 Anal segment wide and buttocks-like in both sexes, but abdomen rounded 



