102 W. A. SANDS 



A. irrixosus is the largest species in the genus, although it is approached in size 

 by A. murcus, the largest A. brevior and A. empodius. The characters separating 

 it from A. murcus have already been noted; other comparisons are made in the 

 discussions of A. ignavus and A. mitis. In A. brevior the proportions of the man- 

 dibles are different in both castes, and the enteric valve seating is sessile. The 

 proportions of the mandibular teeth also distinguish A. empodius which in addition 

 has a prominently lobed sessile enteric valve seating. A. irrixosus was at first 

 grouped with Alyscotermes but this genus has a prominently spined enteric valve, 

 and has the third apical spur well developed on the worker fore tibia, not vestigial. 

 The abdomen of the worker of A. irrixosus appears to be dehiscent, but not very 

 markedly so, since the specimens have not burst completely. 



Holotype $ imago, paratype J imago, workers and nymphs from type-colony, 

 Sudan: Equatoria Province, Imatong Mountains, 24.vii-5.viii.1939 (N. A. Weber), 

 in American Museum of Natural History; paratype $ imago and worker in BMNH. 



Only the type-series is known, and, apart from the comment on the label 'In 

 separate cells in Polyrhachis earth mound, 4500", there is no information on its 

 biology. 



ADYNATOTERMES gen. n. 



(Adynatos, Gr., 'weak, without strength') 



Type-species: Mirotermes (P Procubitermes) moretclae Fuller, 1925 : 191 



Imago. Large-sized, W, 114-1-21. Fore tibia with three apical spurs, third well developed, 

 almost equal to other two. Apical teeth of mandibles short, L A /Li, 0-51-0-57, R A /Ri, 0-73-0-87 ; 

 subsidiary marginal tooth of left mandible with proximal end just level with edge of molar 

 prominence in surface view, complex ratio La/Li. L m , 5-98-6-68. Points of apical and marginal 

 teeth of right mandible in line, anterior edges of marginal teeth equal. Meso- and metanota 

 rather narrow at constriction, M/YV, 0-24-0-28, transverse dark sutures absent. 



Worker. Large, W, 0-85-0-90. Fore tibia weakly swollen. Ti/T w , 4-13-4-54, with three 

 apical spurs, third about half length of other two. Apical teeth of mandibles short, L A /Li, 

 0-53-0-60, Ra/Ri, 0-75-0-82 ; subsidiary marginal tooth of left mandible with proximal end level 

 with edge of molar prominence in surface view, complex ratio La/Li. L m , 10-50-11-86. Points 

 of apical and marginal teeth of right mandible in line, anterior edge of marginal teeth equal, 

 complex ratio Ra/Ri-Riti. 11-90-16-50. Mesenteric junction with proctodeum only slightly 

 angled, almost transverse, to right of malpighian knot. Enteric valve seating with two opposite 

 erect lobes, almost diverticula, connected to second pouch of proctodeum by very short neck, 

 lateroventral in position in unopened abdomen; internal cushions of enteric valve without 

 armature, surface faintly reticulated only. 



This genus contains a single species, and is separated from Astalotermes chiefly 

 on account of the unique development of the enteric valve seating. In the multi- 

 variate similarity analysis, A. moretelae is placed close to Astalotermes empodius, 

 A. aganus and A. mitis, both by clustering methods and when plotted as principal 

 co-ordinates. In the latter it is separable from them only by the value of its ele- 

 ments in the fourth and fifth latent vectors. The canonical variates based on the 

 measurements of both imago and worker castes show the same close similarity to 

 Astalotermes. Thus it was with some hesitation that A. moretelae was consigned 



