176 W. A. SANDS 



the remaining three species, A. sentosus, A. spinulatus and A. tranquilhis. The 

 enteric valve armature of the worker caste, with its extremely long hooked spines, 

 also serves to distinguish it clearly from these species. Even A . spinulatus, which has 

 thin elongated spines, cannot be confused in this respect, especially since it also 

 has longer apical mandibular teeth, and the subsidiary marginal tooth of the left 

 mandible clear of the molar prominence. 



Holotype queen, and paratype workers from type-colony, Democratic Republic 

 of Congo: Kivu, Irangi, i°53'S., 28°28'E., 9.XL1963 (E. Ernst), in British Museum 

 (Natural History) ; paratype king and workers from type-colony, in Swiss Tropical 

 Institute, Basle. 



The smaller nest-chambers of this species were found beneath a typical mound 

 of Thoracotermes macrothorax (Sjostedt) against a tree in rain forest. 



Ateuchotermes sentosus sp. n. 



(Text-figs 448, 449, 456, 457 & 468-473; PL 5, figs 7-9) 



Imago. Head capsule sepia-brown, not darker above ocelli; fontanelle about half size of 

 ocellus, irregular short oval, flat, brown; medial spot short oval, flat, smaller than fontanelle, 

 coloured as head ; postclypeus brown, labrum yellow-brown ; frontal marks smooth flat crescents, 

 coloured as postclypeus; antennae pale yellow -brown. Pronotum brown, meso- and metanota 

 yellow-brown, transverse dark sutures weakly developed; femora yellow, tibiae paler, tarsi 

 yellow-white. Abdominal tergites and dorsal stigmata yellow-brown, sternites paler, ventral 

 stigmata paler than sternites; cerci yellow. 



Posterior margin of head capsule slightly undulating, not evenly rounded; ocelli fairly large, 

 separated from compound eyes by about three-quarters own least diameter; postclypeus 

 weakly inflated, Pcl/W, 025, posterior margin somewhat indistinct, bowed, not evenly rounded, 

 median suture distinct. Apical teeth of mandibles short, La/Li, 0-54, Ra/Pm, 0-83; subsidiary 

 marginal tooth of left mandible with proximal end just clear of molar prominence in surface 

 view, complex ratio, La/Li.Lhi, 6-45; points of apical and marginal teeth of right mandible in 

 line, anterior edge of first marginal longer than that of second. Meso- and metanota fairly 

 wide at constriction. M/W, 0-33. Pilosity of head capsule a fine close even pelt with emergent 

 setae. 



Measurements (one specimen) in millimetres. 



Head width across eyes (W) . . 1 -04 



Ocellus (O w x Oi) . . . 0-09 x 013 



Ocellus to eye (O-E) . . . 007 



Postclypeus length (Pel) . . 0-26 



Antennal article III . . . 0-04 



Antennal article IV . . 006 



Antennal article V . . . 006 



Left mandible, apical to first 



marginal (L A ) . . . 0-09 



Left mandible, first to third mar- 

 ginal (Li) . . . . 0-17 



Left mandible, third marginal to 



molar (L m ) .... 008 



Right mandible, apical to first 



marginal (R A ) • . . . 010 



