NO. I BLACK FLIES OF GUATEMALA — DALMAT IQI 



half, very few hairs intermixed ; R2+3 pilose along apical three-fourths ; 

 Cu2 arcuate ; discal cell absent. 



Legs: Leg i, length, 2.1 mm.; coxa and trochanter light brown; 

 femur light brown except for dark patch at each end ; tibia light brown 

 in midregion, the basal and apical thirds dark brown; tarsus blue 

 black. Leg 2, length, 1.8 mm.; coxa and trochanter light brown; 

 femur dark on basal third, the apical two-thirds light brown except 

 for small apical dark patch ; tibia brown except for basal and median 

 yellow rings ; basal two-thirds of basitarsus yellow, apical third black ; 

 tarsal segments 2-5 black. Leg 3, length, 2.1 mm. ; coxa dark brown; 

 trochanter yellow ; femur and tibia with basal fourth yellow and apical 

 three-fourths dark brown ; basal third of basitarsus and second tarsal 

 segment yellow, the apical two-thirds of each of these segments, as 

 well as all of segments 3-5, dark brown ; relation of basitarsus to 

 second tarsal segment, 4.7 : i ; calcipala well developed, but not reach- 

 ing pedisulcus ; pedisulcus very small, situated on basal third of second 

 tarsal segment. 



Abdomen : Tergite of segment i light brown, pleurites dark brown, 

 the latter with very long tan hairs which reach segment 4. Segment 2 

 light brown. Other segments velvety black, with sparsely distributed, 

 short, tan hairs on last segment. Sternites light brown, with dark 

 brown longitudinal band along midline. 



Genitalia: Sidepiece (pi. 24, fig. 62) wider than long, almost 

 perfect rectangle in shape ; dorsal opening occupying more than half 

 of dorsal surface of sidepiece, following its contours. Clasper (pi. 24, 

 fig. 62) twice as long as wide, almost twice the length of sidepiece, 

 its margins sinuous owing to large bulge near base of inner mar- 

 gin and other toward middle of outer margin ; apex rounded, hardly 

 narrowed, with two well-developed terminal spines next to each other 

 near apical margin. Adminiculum (pi. 24, fig. 61) somewhat in 

 form of inverted Y, the two basal prolongations well sclerotized, 

 spatulate at their ends, with lateral membranes that are continuous 

 with the apical prolongation ; apical prolongation about as long as any 

 one of the basal prolongations, with ventral keel which bears several 

 hairs. Adminicular arms (pi. 24, fig. 63) with about 12 pointed teeth 

 near their ends, arranged in form of a club ; lateral plate somewhat 

 triangular in shape, slightly sclerotized. 



Fe^nale (pi. 31, figs. 181-183, and pi. 35, fig. 241). — 2.5 mm. long. 



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

 triangle twice the base ; both basal angles with extensions to frons. 

 Antenna 450 [x. long, ii-segmented, sharply tapering from the third 

 segment to apex; scape and pedicel tan, flagellum becoming pro- 



