NO. I BLACK FLIES OF GUATEMALA — DALMAT 145 



SimiiUum (Lauca) hacmatopotiim Malloch, Vargas, Martinez, and Diaz, Rev. 

 Inst. Salubr. Enferm. Trop., vol. 7, No. 3, p. 168, fig. 121, 1946 (larva). 



Male (pi. 23, figs. 37-39). — 2.0 mm. long. 



Head: Holoptic. Eyes dark brown, shiny. Antenna 390 ju,, 11- 

 segmented, slightly tapering; segment 3=1+2 = 4+5, 3>ii ; brown, 

 the tip black. Palpi black. Clypeus black, white-pruinose, irregularly 

 covered with short black hairs. 



Thorax : Mesonotum velvety black ; 2 large triangles of white 

 pruinosity, one on either side of midline, the base on the anterior 

 margin, extending slightly more than one-third the length of the 

 mesonotum ; lateral margins and prescutellar region also white- 

 pruinose ; long, narrow, dark-yellow, scalelike hairs around periphery 

 and on midline, not in packets ; row of short tan hairs in prescutellar 

 region. Humeral angles black, white-pruinose, with scalelike hairs. 

 Scutellum very dark brown, with some scalelike hairs and a few long 

 black hairs. Postnotum velvety black, white-pruinose. Pleura dark 

 brown with white pruinosity. Stem of halter brown, the knob bright 

 yellow. Wings, 2.2 mm. long and i.i mm. wide; relation of body 

 length to wing, 1:1.1; Sc pilose along its basal fourth ; Ri spiny 

 along its distal half, with at most 2 hairs among the spines ; R2+3 

 pilose except for small basal portion ; Cu2 arcuate ; discal cell absent. 



Legs: Leg i, length, 2.2 mm.; coxa, trochanter, and femur light 

 brown ; tibia light brown with small apical black ring ; tarsus black. 

 Leg 2, length, 1.8 mm.; coxa black; trochanter brown; femur Hght 

 brown ; tibia dark brown ; basitarsus and tarsal segments 2 and 3 

 light brown ; segments 4 and 5 black. Leg 3, length, 2.2 mm. ; coxa 

 black ; trochanter light brown ; femur black with light-brown basal 

 ring; tibia light brown on basal half, the apical half black; basal two- 

 thirds of basitarsus and basal half of second segment light brown, the 

 remainder of these segments, as well as all of segments 3-5, black ; 

 relation of basitarsus to second segment, 5:1; calcipala well developed, 

 but not reaching pedisulcus ; pedisulcus formed at middle of second 

 segment, not deeply incised. 



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

 pleurites black with long black hairs that reach the fourth segment. 

 Segment 2 black, the pleurites partially white-pruinose, with short 

 black hairs. Other segments black with short black hairs. Sternites 

 tan. 



Genitalia: Sidepiece (pi. 23, fig. 37) somewhat longer than wide, 

 almost square in shape ; dorsal opening occupying approximately half 

 of sidepiece. Clasper (pi. 23, fig. 37) shorter than sidepiece, with broad 

 base, somewhat rectangular in shape, the inner apical angle greatly ex- 



