NO. I BLACK FLIES OF GUATEMALA DALMAT 22/ 



pruinose, with tan to brown hairs. Occipital region black, with short 

 black hairs. Cornuae of buccopharyngeal apparatus heavily sclero- 

 tized, bifurcate, the branches sharply pointed ; median space somewhat 

 sclerotized, with well-formed concavity, and with a single row of 

 large, sclerotized teeth that are like small equilateral triangles in shape. 



Thorax : Mesonotum yellow to orange ; 2 longitudinal bands of 

 pale-yellow pruinosity extending from anterior margin to prescutellar 

 region which is also yellow-pruinose ; yellow pruinosity around entire 

 periphery except between the origins of the two longitudinal bands 

 on the anterior margin; short black hairs on anterior half of meso- 

 notum and in prescutellar region. Humeral angles pale yellow. Scu- 

 tellum yellow with some short black hairs along margin, longer in 

 lateral regions. Postnotum brown, the anterior half white-pruinose. 

 Pleura dark brown, somewhat lighter dorsally, with yellow pruinosity. 

 Stem of halter light brown, the knob yellow. Wings, 2.1 mm. long 

 and i.o mm. wide; relation of body length to wing, i.i : i ; Sc pilose 

 along basal two-thirds ; Ri completely pilose, with spines also along 

 distal two-thirds ; R2+3 pilose except for very small basal section ; Cua 

 arcuate ; discal cell absent. 



Legs: Leg i, length, 2.1 mm.; coxa, trochanter, and femur dark 

 brown; tibia and tarsus black. Leg 2, length, 1.9 mm.; coxa, tro- 

 chanter, and femur dark brown ; basal and apical fourths of tibia black, 

 the median half dark brown ; tarsus black. Leg 3, length, 2.5 mm. ; 

 coxa and trochanter black ; femur dark brown along basal three- 

 fourths and black on apical fourth; tibia black on basal and apical 

 fourths, dark brown on median half ; tarsus black ; relation of basi- 

 tarsus to second tarsal segment, 5.7 : i ; calcipala well developed, over- 

 reaching the pedisulcus ; pedisulcus well formed one-third the distance 

 from the base of second segment ; claw with heel well formed, although 

 not greatly expanded, with subbasal tooth (pi. 35, fig. 250). 



Abdomen : Tergite and pleurites of segment i yellow, with short 

 yellow hairs, the pleurites also with longer ones that reach the third 

 segment. Segments 2-4 yellow ; other segments black ; segments 4-8 

 with short black hairs. Sternites tan, brown toward the rear. 



Genitalia: Cercus (pi. 32, fig, 205) dome-shaped, somewhat 

 higher than long (wide). Anal lobe (pi. 32, fig. 205) about five times 

 higher than it is long (wide), the ventral extremity somewhat pointed ; 

 with projection from its posterior margin that extends somewhat 

 under the cercus. Genital rod (pi. 32, fig. 207) with pronounced basal 

 dilatation ; apical expansions of arms of genital fork irregularly quad- 

 rangular in shape, the margins appearing like small lobelike undula- 

 tions; outer basal angle well sclerotized, pronounced, rounded. Ovi- 



