Head oblong (Figure 389); dorsal surface with two small dark spots at 

 the curvature of the frontal sutures; these spots are sometimes absent or 

 fused; Indistinct light spots posteriorly, lateral to the coronal suture; 

 head dark brown anteriorly on the ventral side; occipital foramen with a 

 dark margin. Head sutures little marked; coronal suture and beginning 

 of frontal sutures represented by a thin light line; gular suture absent. 

 Eyes situated at a distance from the anterior margin; antennae situated 

 near base of mandibles; sensilla of antenna relatively short, with a 

 spherical tubercle at the tip and an upward-directed seta in about the middle 

 of the sensilla; membranous base of the antenna with two pits (Figure 390). 



Head setae fully developed (Figure 389). Anterior-margin setae of 

 clypeus thin; median seta and especially intermediate seta long; lateral 

 anterior -margin seta and anterior -frontal seta curved toward the middle, 

 recumbent; middle and posterior frontal setae long and thin. Setae 9, 12 

 and 17 thick at the base, being some of the longest head setae; seta 11 

 situated near seta 9, small and thin; setae 7, 8 and 10 moderately long, much 

 shorter than seta 9; seta 10 slightly curved, thick at the base; setae 13, 14, 

 15 and 16 long; seta 16 shorter than the others, slightly thickened at the 

 base, like seta 10; ventral seta 18 small. 



Labrum (Figure 391) short and broad; posterior -angle sclerites dark, 

 thin, curved like an S; dorsal sclerite with small processes near the 

 anterior angles; anterior margin of labrum broadly membranous; tufts of 

 long hairs lateral to the shallow median notch; seta 1 thin, curved inward; 

 setae 2, 3 and 4 short, spinelike; seta 6 and especially seta 5 dark, very 

 long. 



Mandibles (Figure 392) short and massive; upper blade of left mandible 

 projecting, rounded, with 3 small denticles distally; lower blade without 

 denticles; brush of chetoids situated in the median notch, forming two rows. 

 Median notch hardly marked on the right mandible; lower blade straight; 

 324 upper blade with two blunt tubercles; the small membranous part in the 

 middle forms two convex folds. 



Maxillolabium brown, darker than head; pregula forming a broad plate, 

 which is concave anteriorly and has a median notch (Figure 393); a process 

 of the posterior margin of the submentum with a slightly concave anterior 

 margin and two strong short setae at the sides corresponds to this notch; 

 cardo short, with a thin curved seta; the oblique ventral sclerite of the 

 stipes with a strong seta near the anterior margin; nearby is the small 

 basal lateral sclerite of the stipes with a large laterally-directed, thick, 

 slightly curved seta, which is the longest seta of the stipes. Anterior seta 

 of maxillary palpifer straight, large, situated near the median angle of the 

 sclerite; small basal seta situated on a membrane. Outer sclerite of 

 galea narrow and oblong, with a ventrobasal process (Figure 394); 

 membranous part of galea with numerous hairs; setae 4, 5, 7 and 9 situated 

 mediodorsally in the middle in a longitudinal row, the first 3 setae club- 

 shaped; the last seta spinelike (like setae 3, 6, 8 of the galea); the two 

 sensillae of group I are replaced by a large sensilla; near it are two spines 

 like sensillae of group II; the sensillae of group III are situated ventrally 

 in the middle; one of them is club-shaped, the other is two-segmented. The 

 sclerite of the 1st segment of the maxillary palp covers only part of the 

 ventral and lateral surface; the sclerites of palp segments 2—4 are 

 complete and ring-shaped. 



355 



