INSECUTOR INSCITI.^J MENSTRUUS 65 



half as long as preceding section. Second aristal joint only 

 moderately elongate, rarely half as long as third joint even in 

 male. Cilia of male facialia marked, always strong and quite 

 thickly placed, ascending well over halfway ; often weaker in 

 female. 



Male lacking outer proclinate fronto-orbitals, female with 

 two. Both sexes with about three inner reclinate fronto-orbi- 

 tals. Both verticals strong, inner ones a little convergent but 

 not decussate, outer ones strongly divergent and shorter; 

 same in both sexes. Two rows of convergent frontals on each 

 side ; two rows of convergent macrochaetae on parafacials of 

 equal strength with frontal rows. Third antennal joint of 

 female only a little longer than the strongly elongate second, 

 about one and one-third times as long ; that of male about two 

 and one-half times as long as the much less elongate second. 

 Second aristal joint is usually conspicuously longer in male 

 than in female, sometimes twice as long. Cilia of facialia 

 wholly or partly doubled in male, single-rowed in female. 

 Proboscis about one and two-thirds times head-height, slender ; 

 palpi slender, filiform, slightly thickened at extreme tip, dis- 

 tinctly shorter than front metatarsi. Cheeks about two-fifths 

 eye-height in both sexes. Front of male but little narrower 

 than that of female, the front very gradually narrowing from 

 face to vertex, the face at root of antennae about one-half 

 head-width. Epistoma greatly and abruptly produced, sub- 

 horizontal or faintly sloping, wedgelike in profile, the lower 

 edge oblique. Four sternopleurals ; four postsuturals, but next 

 to front one often atrophied. Scutellum with three strong 

 laterals, an erect divergent shorter apical pair, and a still 

 shorter discal pair. Abdominal macrochaetae only marginal. 

 Costal spine vestigial. Apical cell ending far before wingtip. 

 Hind crossvein near to bend, nearly parallel with apical, no 

 stump but at most wrinkle at bend. Hind crossvein irregular. 

 Abdomen with long bristly hairs, longest on anal segment. 

 Macrochaetae very long, middle and hind tibiae also with long 

 ones. Female claws strong, but not over half as long as those 

 of male. The frontal and peristomal profiles are subparallel 

 in male, only slightly convergent anteriorly ; in female they are 



