THE SOLDIERLESS TERMITES OF AFRICA 213 



Postclypeus length (Pel) . 0-25-0-29 0264 4j 0106 



Antennal article III . . 002-024 0029 ± 0-006 



Antennal article IV . . 004-005 0041 ± 0-005 



Antennal article V . . 0-04-0-05 0-040 i 0-004 

 Left mandible, apical to first 



marginal (La) • • • 0-07-0-08 0075 ± 0-004 

 Left mandible, first to third 



marginal (Lj) . . . 012-014 OI 33 ± 0007 

 Left mandible, third marginal 



to molar (L m ) . . . 0-06 0061 ± o-ooi 

 Right mandible, apical to first 



marginal (Ha) • • • 0-08-0-09 0080 ± 0-004 

 Right mandible, first to second 



marginal (Ri) . . . 0-09-0-11 0102 ± 0004 

 Right mandible, second mar- 

 ginal to molar (R m ) • ■ 005006 0057 ^ 0-005 

 Mesonotum width (M) . . 0-24-0-28 0-260 ± 0-020 

 Metanotum width (N) . . 0-24-0-29 0270 ± 0020 



Worker. Head capsule pale yellow, pilosity yellow, setae sparse. Postclypeus rather strongly 

 inflated, Pcl/W, 0-31-0-34. Pcl/Ri, 2-47-2-67. Apical teeth of mandibles short, La/Li, 

 '59-°'°4. Ra/R-i. 0-78-0-82; subsidiary marginal tooth of left mandible separated from molar 

 plate by distinct notch in surface view, complex ratio, La/Li. L m , 12-20-13-49; point of first 

 marginal tooth of right mandible slightly behind line of apical to second marginal, anterior 

 edges of marginal teeth equal in length, RA/Ri-Rm. 15-12-18-60. Fore tibia scarcely swollen, 

 Ti/T w , 4-51-4-73, third apical spur about one-third length of other two, pale and inconspicuous 

 Mesenteric overlap with proctodeum rather short, less than three times as long as width of 

 mesenteron at insertion of malpighian tubules; enteric valve seating with two very weakly 

 developed opposed lobes and a very small third inner lobe, connected to second pouch of 

 proctodeum by a short neck; lateral in position in unopened abdomen; internal cushions of 

 enteric valve all retracted, about equally developed, with scaly surface only; membranous wall 

 of valve between and beyond cushions with sparse minute spicules. 



Measurements (three specimens from separate nest series) in millimetres. 



Head width (W) .... 



Fore tibia width (T w ) . 

 Fore tibia length (Ti) 

 Postclypeus length (Pel) 

 Left mandible, apical to first marginal (La) 

 Left mandible, first to third marginal (Li) 

 Left mandible, third marginal to molar (Lm 

 Right mandible, apical to first marginal (Ra) 

 Right mandible, first to second marginal (Ri) 

 Right mandible, second marginal to molar (R 



A . improelatans has already been compared with all those preceding it alphabetic- 

 ally. It is easily recognized by its rather wider meso- and metanotal constrictions 

 in the imago and its shorter mixed segment in the worker, quite apart from the 

 different proportions of the mandibles in both castes. The remaining two species 

 of the genus, A. nanus and A. polyscolus, are both smaller, with rather flattened 

 compound eyes in the imago. In the worker caste, both have spiny armature in the 

 enteric valve. 



Range 



Mean 



0-74-0-78 



0761 



011-012 



— 



o-5i-o-54 



0-525 



0-24-0-25 



°-244 



0-07-0-08 



0075 



012-013 



0123 



004-005 



0-048 



007-008 



0076 



0-09-0- 10 



0095 



0-04—0-05 



0-048 



