AET,22 LITTLE KNOWN DIPTERA ALDRICH 21 



entire series of frontal bristles reclinate, and back of head with only 

 white hair behind the single row of orbital cilia. 



Eyes bare, front narrow above, ocellars minute, proclinate, frontals 

 extending to tip of second antennal joint; parafacials bare, narrow, 

 frontal ridges with bristles almost meeting lowest frontals. Face 

 only a Httle receding; vibrissae at edge of mouth. Palpi normal, 

 proboscis small. Antennae slender, second joint more than half the 

 third, which reaches almost to vibrissae; arista slender, bare, basal 

 joints short. 



Thoracic chaetotaxy of genotype: Acrostichal, 3, 3; dorsocentral, 

 2, 3; humeral, 4; posthumeral, 1; presutural, 2; notopleural, 2; supra- 

 alar, 3; intraalar, 3; postalar, 2; sternopleural, 1, 1; scutellum, with 

 tliree lateral, one irregular and upturned apical. 



Abdomen with discals, several pairs large and small, more numer- 

 ous in male. 



Wing with petiolate apical cell, the third vein ending far before 

 tip. Veins bare except a few hairs at base of third. 



Type of genus. — Simoma grahami, new species. 



SIMOMA GRAHAMI, new species 



Male. — Color black throughout, including antennae and palpi. 

 Front narrow, 0.17 of head width (three measured 0.17, 0.17, and 

 0.18); the frontal stripe black, very narrow near the ocelli. Para- 

 frontals comparatively broad, shining black above, gradually chang- 

 ing to silvery on the parafacials, a single pair of large verticals; the 

 frontal row slightly double in the diverging part below; cheek about 

 one-fourth of eye height, bristly almost to the eye. 



Thorax subshining black; viewed from behind the dorsum has 

 enough pruinosity to leave four incomplete black stripes. Scutellum 

 wholly subshining black; postscutellum pollinose. Calypters white, 

 the hind one with a slight and variable infuscation. 



Abdomen in some Ughts almost shining black or with slight bluish 

 metalhc tinge, in other directions showing a considerable amount of 

 pollen except on the tips of segments. Several pairs of erect bristles 

 of varying size are present on each of second, third, and fourth seg- 

 ments. Venter entirely shining with a slight metalhc tinge. Legs 

 black; pulvilh moderately elongated and distinctly infuscated. Mid- 

 dle tibia with two bristles on outer front side near middle; hind tibia 

 with a rather uniform row of bristles on the outer side, interrupted 

 by one longer just below the middle. 



Wing distinctly infuscated, third vein with about three bristles at 

 base; costal spine present but small, last section of fifth vein barely 

 one-third the preceding. 



Female. — Front considerably wider than in the male, gradually 

 narrowing to the vertex, where in three specimens it measures 0.22, 



