158 W. A. SANDS 



Museum (Natural History). Democratic Republic of Congo: Kivu, Irangi, 

 2.XI.1963 (E. Ernst) Swiss Tropical Institute, Basle and BMNH. 



The type-series was found in the top 3-4 inches of soil on a mound of Protermes 

 prorepens (Macrotermitinae) in rain forest. 



ATEUCHOTERMES gen. n. 



(Ateuches, Gr., 'unarmed') 



Type-species: Ateuchotermes pectinatus sp. n. 



Imago. Medium-sized to large, W, 0-90-1-30. Fore tibia with three apical spurs, third 

 well developed, one-third or more length of other two, except in one species in which it is 

 vestigial. Apical teeth of mandibles short or fairly short, La/Li, 0-50-0-66, Ra/Ri, o-66-i-oi; 

 subsidiary marginal tooth of left mandible with proximal end just clear to widely clear of molar 

 prominence in surface view, complex ratio, La/Li. L m , 533-910; points of apical and marginal 

 teeth of right mandible in line, or first marginal retracted slightly behind line of apical to second 

 marginal, anterior edge of first marginal equal to that of second, or longer. Meso- and metanota 

 rather narrow to distinctly wider at constriction, M/W, 0-26-0-34, transverse dark sutures weak 

 or absent on mesonotum in most species, only distinct in one, present or absent on metanotum; 

 complex ratio of mandible and notal measurements, Li/M.N, 1-07-1-92. 



Worker. Medium sized to very large, W, 0-75-1-10. Fore tibia scarcely swollen or slender- 

 Ti/T w , 4-72-5-90, with three apical spurs, third small or vestigial, maximum about one-third 

 of other two. Apical teeth of mandibles short to moderately long, La/Li, 0-45-0-74, Ra/Ri, 

 0-59-1-01; subsidiary marginal tooth of left mandible with proximal end level with edge of 

 molar prominence (one species only) or distinctly clear of it in surface view, complex ratio, 

 La/Li. L m , 8-32-14-41 ; points of apical and marginal teeth of right mandible more or less in line, 

 or first marginal distinctly retracted behind line of apical to second marginal, anterior edge of 

 first marginal equal to that of second or markedly shorter, complex ratio, Ra/RiRiti, 10-40- 

 17-10. Mesenteric junction with proctodeum diagonal or a little longer, to right of malpighian 

 knot. Enteric valve-seating rather large, weakly two-lobed, sessile on second pouch of procto- 

 deum or connected to it by short neck, dorsolateral to dorsal in unopened abdomen; internal 

 cushions of enteric valve all sclerotized and produced through valve opening, that in position 1 

 enlarged, elongated, and dilated at its posterior end which curves out into enteric valve seating; 

 armature in position 1 numerous elongated spines in comb- or rake-like formation in one or more 

 rows round rim; armature in positions 2, 3 and 4 elongated, more slender spines, sometimes 

 hooked at tips, fewer in number than position 1, in fork-like formation at posterior ends of 

 cushions; all cushions sometimes with small spines on remainder of length or without further 

 armature. 



The enteric valve armature of the worker caste of Ateuchotermes is the most 

 complex in the entire group and the most easily recognized. The function of this 

 fantastic structure can only be a source of speculation. The cushion in position 1 

 has elongated to an extent where it hooks out of the enteric valve itself into its 

 seating. Its spines touch the wall of the seating, where in one species a sclerotized 

 cup has developed to receive them. The teeth of this structure are too far out 

 to act as a filter. Only two possibilities suggest themselves. It could hold a colony 

 of symbiotic bacteria against the wall of the gut and prevent their dispersion; or 

 it could form a springy linking device to prevent the enteric valve pulling out of its 

 seating. This in some other genera it seems to do very easily, in preserved material, 

 being almost impossible to keep in place in dissections. It may be envisaged that 



