210 W. A. SANDS 



retracted and about equally developed, with scaly surface only; membranous wall of valve 

 between cushions with very sparse minute spicules. 



Measurements (one specimen) in millimetres. 



Head width (W) 0-84 



Fore tibia width (T w ) .... 0-13 



Fore tibia length (Ti) .... 0-56 



Postclypeus length (Pel) . . . 0-22 



Left mandible, apical to first marginal (L A ) 009 



Left mandible, first to third marginal (Li) . 015 

 Left mandible, third marginal to molar 



(L m ) ...... 006 



Right mandible, apical to first marginal 



(Ra) 0-09 



Right mandible, first to second marginal 



(Ri) oi 3 



Right mandible, second marginal to molar 



(Rm) 0-05 



A. hemerus is the largest species of the genus. Comparisons with A. amachetus, 

 A. ateuchestes, A. cicur, A. cnaphorns and A. dislnctans have already been made. Of 

 the remaining species, A. improcinctus, A. nanus and A. polyscolus are all much 

 smaller and so unlikely to be confused with it. A. improelatans is also smaller, 

 but less markedly so. In the imago it is recognizable by its less constricted meso- 

 and metanota, and very small fontanelle; in the worker caste the first marginal 

 tooth of the right mandible is as long as the second and the mixed segment of the gut 

 is shorter. 



The abdomen of the worker appears to be dehiscent in A. hemerus. 



Holotype $ imago, paratype <$ and $ imagos and workers from type-colony, 

 Sudan: Mount Bangenze, 4°3o'N., 30°oo'E., 15. v. 1937 (J. G. Myers) in American 

 Museum of Natural History ; paratype $ and <$ imagos and workers from type-colony 

 also in BMNH. 



Only the type nest-series is known; there is no biological information. It is 

 known to the Zande tribesmen in the area as 'Akpiaru'. 



Anenteotermes improcinctus sp. n. 



(Text-figs 567-570 & 583-588) 



Imago. Head capsule sepia-brown, darker above ocelli; fontanelle very small elongate oval, 

 flat or slightly depressed, brown, almost obsolete in some specimens; medial spot also very 

 small, elongate oval, flat, coloured as head; postclypeus brown, labrum pale yellow-brown; 

 frontal marks smooth, flat, semicircular, coloured as head; antennae pale brown to brown. 

 Pronotum, meso- and metanota, brown, transverse sutures present; femora and tibiae pale 

 brown, tarsi pale yellow. Abdominal tergites and dorsal stigmata brown, sternites pale brown, 

 paler in middle, ventral stigmata pale; cerci pale yellow-brown. 



Posterior margin of head capsule evenly rounded; ocelli rather small, separated from some- 

 what flattened compound eyes by one-quarter to slightly over one-third own least diameter; 

 postclypeus rather strongly inflated, Pcl/W, 0-30-0-34, posterior margin evenly rounded, median 

 suture only distinct in middle. Apical teeth of mandibles short, La/Li, 0-50-0-60, Ra/Ri, 



