THE SOLDIERLESS TERMITES OF AFRICA 55 



Group III. Medium-sized to larger species, W, (Imago) 076-1-20; apical teeth 

 of mandibles somewhat shorter. La/Li, (Imago) 0-41-0-64, (Worker) 0-43-0-64; 

 right mandible of worker with anterior edge at first marginal tooth much shorter 

 than that of second; imago, meso- and metanota variably somewhat wider than 

 Group I. M/W, 0-23-0-34; worker enteric valve seating ventro- to dorsolateral in 

 unopened abdomen, sessile or short-necked, weakly two- or three-lobed. Species 

 included: A. acholics sp. n., A. brevior (Holmgren), A. obstructus sp. n., A. quietus 

 (Silvestri). This group is the most specialized in the genus, with the distinctly 

 reduced first marginal tooth of the right mandible. This reduction looks like an 

 adaptation to soil-feeding alternative to the commoner form in which the elongated 

 apical tooth becomes widely spaced from the first marginal and the second marginal 

 is reduced. The wide space between the pick-like apical and the second marginal 

 produced by the suppression of the first marginal achieves a similar result. This 

 feature is again found in Anenteotermes, and the slightly longer mesenteric overlap 

 with the proctodeum found in Group III may be a further indication of relationship 

 with that genus. 



Other Species. Three species do not fit readily into any group. A. impedians sp. 

 n. is a medium-sized species which most resembles Group I but has shorter apical 

 teeth to the mandibles and somewhat wider meso- and metanota. The latter 

 feature, with the long necked, rather prominently lobed enteric valve seating, 

 suggest affinities with Group II. A. empodius sp. n. is closest to Group II but the 

 strongly lobed sessile, dorsolateral enteric valve seating in the worker and narrow 

 meso- and metanota in the imago add to a general similarity of appearance to 

 Adynatotermes, which is borne out by its position in the principal co-ordinates 

 analysis. A. irrixosus sp. n., like the previous species, was at first included in 

 Group II, but its larger size, the proportions of the mandibles, the slender fore 

 tibia of the worker and the wider imaginal meso- and metanota suggest affinities 

 with Astratotermes and Aly scoter mes. It also has the enteric valve seating dorso- 

 lateral in the worker abdomen. 



Key to Species 

 Imagos 



Right mandible with anterior edge of first marginal tooth at least as long as anterior 

 edge of second marginal (where second marginal connected to posterior edge of 

 first by a continuous curve, lowest point to be regarded as beginning of second) . 2 



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



edge of second marginal .......... 16 



Pilosity of head capsule consists of short somewhat uneven pelt with very long 

 emergent setae, many of them over 0-2 mm; those near compound eyes extending 

 beyond outer curve of eye by nearly half their length ..... 3 



Pilosity of head capsule shorter, emergent setae, where distinct, at most only slightly 



beyond curve of eye ........... 4 



Meso- and metanota proportionately wider at constriction, M/W, 0-31-0-32 



ignavus (p. 75) 



Meso- and metanota narrower at constriction, M/W, 0-26-0-27 • • murcus (p. 79) 



