NO. I BLACK FLIES OF GUATEMALA — DALMAT I27 



Legs: Leg i, length, 3.1 mm. ; coxa yellow; trochanter and femur 

 light brown ; tibia brown with its anterior margin and apical fourth 

 darker ; tarsus dark brown. Leg 2, length, 1.8 mm. ; coxa dark brown ; 

 trochanter light brown ; femur very hairy, light brown, with anterior 

 margin and very small apical region dark brown ; tibia brown on basal 

 third, dark brown on apical two-thirds, very hairy ; basal half of basi- 

 tarsus brown, the apical half black ; tarsal segments 2-5 black ; basi- 

 tarsus and second segment with several apical spines. Leg 3, length, 

 3.4 mm. ; coxa dark brown ; trochanter light brown ; femur light brown 

 with its apical fourth and posterior margin dark brown ; very hairy, 

 with apical spines ; tibia black with brown basal ring, very hairy, with 

 2 apical spines ; basitarsus reddish brown, very hairy, tarsal segments 

 2-5 black; relation of basitarsus to second segment, 5.4: i ; calcipala 

 well developed, overlapping the pedisulcus; pedisulcus formed on 

 basal third of second segment. 



Abdomen : Tergite of segment i yellow, with short black hairs ; 

 pleurites yellow, with very long black hairs that reach beyond the 

 third segment. Segment 2 yellowish brown, with short black hairs. 

 Other segments velvety black, the pleura brown, with short black 

 hairs ; pleura of segments 6 and 7 with patch of silvery pruinosity. 

 Sternites black. 



Genitalia: Sidepiece (pi. 23, fig. 25) cylindrical in shape, twice 

 as long as it is wide ; dorsal opening occupying less than half of the 

 dorsal surface of sidepiece. Clasper (pi. 23, fig. 25) almost rectangu- 

 lar in shape, much longer than wide, shorter than sidepiece, the distal 

 end broader than the base ; outer apical angle rounded and somewhat 

 extended, the inner apical angle pointed, with a single short terminal 

 spine at its apex. Body of adminiculum (pi. 23, fig. 26) shield-shaped, 

 slightly longer than wide, the apex somewhat pointed ; ventral surface 

 with numerous short hairs ; basal processes short, narrow, ending in 

 point, strongly sclerotized. Arms of adminiculum (pi. 23, fig. 27) 

 with about 24 teeth arranged in linear fashion, long and short ones 

 intermixed ; lateral plate elongate. 



Female (pi. 29, figs. 142-144, and pi. 35, fig. 259). — 3.1 mm. long. 



Head: Dichoptic. Eyes dark reddish brown; height of fronto- 

 ocular triangle 1.5 times the base. Antenna 450 fi long, ii-segmented, 

 slightly tapering; segment 3 = 4-f5, 3= or<i+2, 3=11, scape and 

 pedicel light brown, flagellum dark brown. Palpi black. Frons and 

 clypeus brown, white-pruinose, with short black hairs. Occipital re- 

 gion dark brown, with many black hairs and some that appear lighter 

 in color. Cornuae of buccopharyngeal apparatus narrow, blunt, scle- 

 rotized ; median space slightly sclerotized, smooth, without teeth. 



