152 W. A. SANDS 



The comparisons of this, the type-species, with the remaining members of the 

 genus, have already been made under their individual headings. The abdomen 

 seems to be weakly dehiscent in the worker caste of A. tithasus. 



Holotype $ imago, paratype <$ and $ imagos and workers from type-colony, 

 Democratic Republic of Congo: Yangambi, 29.V.1948 {A. E. Emerson), in 

 American Museum of Natural History. (Paratypes from type-colony, $ and $ 

 imagos and workers, also in BMNH.) 



The single known nest-series was found in a mound 5 ft in diameter, 3 ft high, 

 at the base of a tree. 



AMICOTERMES gen. n. 



(Amicus, L., 'friend(ly), kind') 

 Type-species: Amicotermes galcnus sp. n. 



Imago. Medium-sized, \V, i-oi. Compound eyes proportionately rather small, W/E, 45 

 (all other genera and species under 4-2, most under 40). Fore tibia with three apical spurs, 

 third very small, almost vestigial; fore coxae thickly setose, somewhat spiny on anterior edge. 

 Apical teeth of mandibles very long, La/Li, 0-99. Ra/Ri, 1-36; subsidiary marginal tooth of 

 right mandible with proximal end just clear of molar prominence in surface view, complex 

 ratio, La/Li. L m , 14-08. Point of first marginal tooth of right mandible distinctly behind line 

 of apical to second marginal, anterior edges of first and second marginals subequal. Meso- and 

 metanota rather narrow at constriction, M/W, 0-28, transverse dark sutures absent; complex 

 ratio of mandible and notal measurements, Li/M.N, i-6o. 



Worker. Medium-sized, W, 0-76. Fore tibia weakly swollen, Ti/T Wl 432, with three apical 

 spurs, third spur small, about one-third other two; fore coxae and rest of leg strongly setose, 

 bristly, apex of tibia and base of femur with opposing interlocking bristles when folded (only 

 genus in which this is found). Apical teeth of mandibles very long, La/Li, 1-09, Ra/Ri, i*33J 

 subsidiary marginal tooth of left mandible just clear of molar prominence in surface view, 

 complex ratio La/I-i-Liti, 26-50; point of first marginal tooth of right mandible distinctly behind 

 line of apical to second marginal, anterior edges of first and second marginals subequal, complex 

 ratio, Ra/Ri-Rih, 3i -2 5- Mesenteric junction with proctodeum nearly transverse, slightly 

 angled, to right of malpighian knot. Enteric valve seating definitely three-lobed, third lobe 

 only slightly smaller than outer two, connected to second pouch of proctodeum by very long 

 neck, lateral in position in unopened abdomen; internal cushions of enteric valve produced 

 through valve opening, those in position 3 slightly more elongated than the others, all positions 

 armed in posterior one-third of length with numerous irregularly arranged elongated spines; 

 rest of cushion surface scaly, most scales edged with small or minute spines. Membranous 

 wall of valve beyond cushions with numerous fine but pronounced spicules, between cushions 

 with numerous spicule-fringed carunculations. 



Amicotermes was at first grouped with Acholotermes on the basis of the similarity 

 of the imago and worker mandibles, and the layout of the worker gut. However, 

 the worker enteric valve-armature is much more developed, and the imago rather 

 different in appearance with its unusually small compound eyes. The spiny or 

 setose coxae of worker and imago are another unusual feature supporting the place- 

 ment of the single species in a monotypic genus. The vector and cluster analyses 

 of the similarity matrix also separate it widely from Acholotermes. The enteric 

 valve armature of Amicotermes is superficially similar to that of Apagotermes, but 

 in the latter genus the imago and worker mandibles are quite different, and the valve 



