58 W. A. SANDS 



9 Enteric valve seating ventrolateral in unopened abdomen. Smaller, W, 070, 

 Ti, 0-46, fore tibia more inflated, Ti/T w , 4-02. 'Abdominal dehiscence' absent 



acholus (p. 82) 



- Enteric valve seating dorsolateral in unopened abdomen. Larger, W, 0-71-0-93, 



Ti, 0-50-0-66, fore tibia less inflated, Ti/T w , 4-21-5-52. 'Abdominal dehiscence' 



very frequent ............ 10 



10 Armature of enteric valve with a few minute spines on the proximal one-third of 



cushions in positions 3 and 4. (Distribution, South Africa to Angola) brevior (p. 84) 



- Enteric valve cushions scaly, without spines. (Distribution, W. Africa to Uganda, 



and Congo) .......... quietus (p. 91) 



11 Larger, W, 0-88-0-91 ........... 12 



- Smaller, W, 0-64-0-77 ........... 13 



12 Enteric valve seating with two prominent lobes only, lateral in unopened abdomen. 



Mesenteric-proctodeal junction diagonal ..... hapalus (p. 72) 



- Enteric valve seating with three prominent lobes, third almost equal, ventrolateral 



in unopened abdomen. Mesenteric-proctodeal junction nearly transverse 



aganus (p. 69) 



13 Right mandible with anterior edge of first marginal tooth distinctly shorter than 



anterior edge of second ....... obstructus (p. 88) 



- Right mandible with anterior edge of first marginal approximately equal to second . 14 



14 Fore tibia more inflated, Ti/T w , 3-86-3-88. Apical teeth of mandibles longer, 



La/Li, 0-69-0-86, Ra/Ri, 0-97-1-00 ........ 15 



- Fore tibia less inflated, Ti/T w , 4-22-4-47. Apical teeth of mandibles shorter, L A /Li, 



0-54-0-67. R A /Ri, 0-72-0-92 ...... ... 16 



15 Larger, W, 077, Ti, o-6i. Left mandible with subsidiary marginal tooth just clear 



of molar prominence. Complex ratio Ra/T\ v .Li, 4-46 . . amicus (p. 58) 



- Smaller, \V, 0-64, Ti, 0-43. Left mandible with subsidiary marginal tooth separated 



from molar prominence by deep notch. Complex ratio R A /T w .Li, 7-20 



eumenus (p. 67) 



16 Apical teeth of mandibles proportionately shorter, La/Li, 054; left mandible with 



subsidiary marginal tooth separated from molar prominence by deep notch, 

 LA/Li.L m , 12-45. (Distribution, Zambia) .... impedians (p. 98) 



- Apical teeth proportionately longer, La/Li, 0-59-0-67; left mandible with subsidiary 



marginal tooth just clear of molar prominence, La/Li. L m , 15-65-17-79. (Distri- 

 bution, West Africa) ........ concilians (p. 65) 



Group I 

 Astalotermes amicus sp. n. 



(Text-figs 57, 58, 67, 68 & 77-82; PI. 1, fig. 4) 



Imago. Head capsule brown, not darker above ocelli; fontanelle small, about one-third 

 size of ocellus, roughly circular with small depression in middle, pale yellow-brown; medial 

 spot roughly circular, flat or slightly raised, little smaller than fontanelle, yellow-brown; 

 postclypeus yellow-brown, labrum yellow; frontal marks flat, almost obsolete, weak crescents, 

 yellow-brown ; antennae yellow. Pronotum, meso- and metanota yellow-brown, transverse 

 sutures present but weak; legs, femora yellow, tibiae pale yellow, tarsi yellow-white. Ab- 

 dominal tergites yellow-brown, sternites, dorsal and ventral stigmata pale yellow-brown, 

 cerci pale yellow. 



Posterior margin of head capsule evenly rounded; ocelli medium-sized, separated from 

 compound eyes by half own least diameter or slightly more; postclypeus moderately inflated, 

 Pcl/W, 0-25-0-26, Pc1/Ra, 1-93-2-00, posterior margin evenly rounded, median suture very 

 weak. Apical teeth of mandibles rather long, La/Li, 0-71-0-79, Ra/Ri, 1-04-1-05; subsidiary 



