ETHIOPIAN XASUTITERMITINAE 133 



Trinervitermes hentschelianus (Sjostedt) Sjostedt, 1926 : 344. 



Nasirfitermes (Trinervitermes) messor (Sjostedt) Emerson, 1928 : 416. 



Trinervitermes hilli Snyder and Emerson ; in Snyder, 1949 : 327. [n. n. for Eutermes (Triner- 

 vitermes) bulbiceps Holmgren, junior primary homonym of Eutermes (Eutermes) bulbiceps 

 Holmgren.] syn. n. 



Imago. Head capsule, frons and vertex yellow-brown to dark sepia brown, sometimes paler 

 around eyes, in front of ocelli, and bordering posterior margin of postclypeus ; vertex with or 

 without one to three diverging paler streaks ; labrum yellow, postclypeus yellow to yellow- 

 brown, strikingly paler than head in dark forms ; antennae yellow to yellow-brown. Pronotum 

 yellow to sepia brown, meso- and metanota yellow to yellow-brown, other thoracic sclerites and 

 legs yellow. Abdominal tergites brown, sepia brown around stigmata ; sternites pale yellow, 

 brown around stigmata. Wings translucent yellow-brown to brown, subcosta and radius 

 sector yellow to brown, outlined brown to dark brown at base ; membrane behind radius sector 

 with a very weakly developed yellow streak or none ; rest of venation narrowly brown or 

 outlined brown. 



Posterior margin of head capsule behind eyes varies from distinctly less than semi-circular to 

 nearly semi-circular, very weakly or not sinuate immediately behind eyes ; fontanelle pale, 

 contrasting with surrounding cuticle especially in dark forms, usually elongate Y-shaped, 

 lateral arms short to long, often dilated terminally, middle of fontanelle sometimes slightly 

 depressed ; eyes very short oval, prominent in proportion to own diameter, but small to medium- 

 sized relative to head width, W/E index 3-3-3-9 , ocelli small to medium-sized, separated from 

 eyes by from slightly over one-third to more than own least diameter ; postclypeus moderately 

 to strongly inflated, width 1-8-2-4 times length, anterior margin straight or slightly concave, 

 posterior margin convex, evenly rounded ; molar plate of right mandible with 8-10 ridges, 

 usually 9 ; antennae 15-17 segmented, proportions of basal segments variable, partly subdivided 

 in 15 segmented forms. 



Pale coloured " scent " gland on anterior margin of $ fifth abdominal sternite small, 0-46- 

 0-56111111. wide, o-i3-o-2omm. long ; cerci of $ slightly shorter to slightly longer than width 

 across base, conical or slightly mamilliform. 



Pilosity of vertex rather sparse, of varying length, setae not forming a " pelt " or " mat ". 

 Measurements (43 specimens from 25 localities) in millimetres. 



Range Mean 



Head width across eyes 1-61-2-03 • • \%o 



Greatest diameter of eye 0-43-0-56 . . 0-50 



Ocellus . . . 010-0-23 x 0-16-0-25 • 018 x 024 



Ocellus to eye . . 007-015 . . 010 



Width of pronotum . 1 -48-1 94 . . 1 -66 



Length of pronotum . 0-92-1-18 . . 0-99 



Length of hind tibia . 2-02-2-47 . . 2-26 



Length of fore wing . 15-30-22-60 . . I 9'37 



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

 to pitch black with red tip ; antennae yellow to yellow-brown. Pronotum, meso- and meta- 

 nota, legs and abdominal sternites yellow, abdominal tergites yellow to brown. 



Head capsule in plan view, short oval to wider than long, often with posterior median indent- 

 ation in larger specimens, nose cylindrical to weakly conical. In profile distinctly concave to 

 well behind antennal socket, convex curve to occiput most pronounced at posterior extremity 

 of head ; nose distinctly shorter to distinctly longer than rest of head capsule measuring from 

 hind margin of antennal socket, angle of nose cone 0-14 degrees ; antennae 14 segmented, II, 

 III, IV, V, and VI subequal, rarely 13 segmented, when III nearly twice II. Head setae 

 mainly confined to hairy nose tip ; bilaterally placed pair of minute setae sometimes present 

 on vertex. 



Abdominal tergites with scattered minute setae and longer setae on hind margins, becoming 

 more pronounced on posterior tergites ; sternites with scattered shorter backwardly directed 



