io6 



W. A. SANDS 



Eutermes (Trinervitermes) oeconomus Tragardh ; Holmgren, 191 2 : 64. 



Eutermes (Trinervitermes) mobilis Sjostedt ; Holmgren, 1912 : 65. 



Eutermes (Trinervitermes) tchadensis Sjostedt ; Holmgren, 1912 : 68. 



Eutermes schubotzianus Sjostedt, 1914b : 93. Type locality : Chad, Ft. Crampel. 



Eutermes (Trinervitermes) schubotzianus Sjostedt ; Hegh, 1922 : 693. 



Trinervitermes oeconomus (Tragardh) Sjostedt, 1925a : 73. 



Trinervitermes tchadensis (Sjostedt) Sjostedt, 1926 : 353. 



Trinervitermes schubotzianus (Sjostedt) Sjostedt, 1926 : 383. 



Trinervitermes mobilis (Sjostedt) Sjostedt, 1926 : 353. 



syn. n. 



Imago. Head capsule, central part of frons and vertex brown to dark chestnut brown ; 

 vertex with three diverging yellow-brown streaks ; postclypeus, and area surrounding eyes, 

 extending to a point behind eyes and to mandible base in front, yellow-brown ; labrum and 

 antennae yellow to yellow-brown. Pronotum yellow to yellow-brown, meso- and metanota, 

 other thoracic sclerites and legs yellow. Abdominal tergites brown to dark chestnut brown, 

 slightly darker round stigmata, with yellow to yellow-brown border, and slightly paler towards 

 lateral corners of front margin ; sternites yellow to yellow-brown, brown round stigmata. 

 Wings translucent pale brown, subcosta and radius sector yellow, paler distally, latter outlined 

 brown at base, membrane between them shaded brown for short distance from suture ; mem- 

 brane behind radius sector with or without orange-yellow streak ; rest of venation narrowly 

 yellow-brown to brown. 



Posterior margin of head capsule behind eyes much less than semi-circular, slightly sinuate 

 immediately behind eyes ; fontanelle distinct, usually Y-shaped with lateral arms dilated 

 terminally, sometimes slightly depressed or occluded posteriorly, length approximately twice 

 breadth at base of lateral arms ; eyes slightly angularly oval and moderately prominent in 

 proportion to own diameter, medium-sized relative to head width, W/E index 2-6-3-0 ; ocelli 

 medium sized to large, separated from eyes by one-fifteenth to one-fourth own least diameter ; 

 postclypeus moderately inflated, width 2-3 to 25 times length, anterior margin nearly straight, 

 posterior margin convex, rounded ; molar plate of right mandible with 7-8 ridges ; antennae 

 17 segmented, II, IV, and V subequal, VI slightly and III distinctly longer than these. 



Pale coloured " scent " gland on anterior margin of fifth abdominal sternite of $ large, 

 0-97— 1 -07mm. wide, o-26-o-4imm. long ; cerci of ? longer than wide across base, conical. 



Pilosity of vertex of varying length, setae not forming a " pelt " or " mat " (Text-fig. 384). 



Measurements (40 specimens from 9 localities) in millimetres. 



Range Mean 



1-72-1-95 . . 1-82 



0-58-0-74 . . o-66 



0-19-0-25 X 0-25-0-31 . . 0-22 X 0-28 



OO2-OO5 . . OO3 



I-58-I-95 . . 1-69 



O98-I 18 . . I-09 



2-30-2-68 . . 2-48 



1610-20-80 . . 1861 



Soldiers. Major soldier ; head capsule yellow to ferruginous, commonly orange-yellow, nose 

 orange to chestnut brown with reddish tip. Antennae and pronotum orange-yellow, meso- and 

 metanota, and legs yellow. Abdominal tergites brown, sternites pale yellow. 



Head capsule in plan view short oval or circular, nose conical. In profile near straight to 

 distinctly concave, with back of head rising from above antennal socket, and rounded ; nose 

 equal in length to distinctly shorter than rest of head capsule, measuring from hind margin of 

 antennal socket, angle of nose cone 5-18 degrees ; antennae 13-14 segmented, only one in 

 twenty with 13, proportions of basal segments variable, in 13 segmented forms, II and IV sub- 

 equal, shorter than V and VI which are also subequal, III twice II and IV, in 14 segmented, 

 III, V and VI subequal, IV slightly longer and II slightly shorter. Head setae confined to four 



Head width across eyes 

 Greatest diameter of eye 

 Ocellus 

 Ocellus to eye 

 Width of pronotum 

 Length of pronotum 

 Length of hind tibia 

 Length of fore wing 



