u6 W. A. SANDS 



Astratotermes hilarus sp. n. 



(Text-figs 248, 249, 254, 255 & 268-273 ; PI. 2, fig. 2) 



Imago. (Queens and kings only available, colours may be faded.) Head capsule chestnut- 

 brown, darker above ocelli; fontanelle nearly same size as ocellus, slightly raised, short oval, 

 brown; medial spot very small, slightly raised, circular, coloured as head; postclypeus brown, 

 labrum yellow; frontal marks indistinct flat brown crescents; antennae brown. Pronotum, 

 meso- and metanota brown, transverse dark sutures very distinct; legs, femora pale brown, 

 tibia yellow-brown, tarsi yellow. Abdominal tergites and dorsal stigmata brown, ventral 

 stigmata and sternites pale brown laterally, yellow in middle; cerci pale yellow-brown. 



Posterior margin of head capsule evenly rounded; ocelli medium-sized, separated from com- 

 pound eyes by two-thirds up to own least diameter, postclypeus weakly inflated, Pcl/W, 0-2 1- 

 0-24, posterior margin arched, not evenly rounded, median suture weakly developed. Apical 

 teeth of mandibles moderately long, La/Li, 0-67-0-80, R A /Ri, 0-95-1-07; subsidiary marginal 

 tooth of left mandible widely separated from molar prominence in surface view, L A /Li L m , 

 10-07-11-11; point of first marginal tooth of right mandible slightly behind line of apical to 

 second marginal, anterior edges of marginal teeth approximately equal. Meso- and metanota 

 rather narrow at constriction, M/W, 0-24-0-28. Pilosity of head capsule brown, uneven, no 

 pelt. 



Measurements (five specimens from three nest-series) in millimetres. 



Range Mean ± S.D. 



Head width across eyes (VV) . 1-03-1-06 1-041 ± 0-016 

 Ocellus (O w x Oi) . . . 007-010 x 010-012 0084 ± o-oio x 0-113 ±0-009 



Ocellus to eye (O-E) . . 0-06-0-09 0-067 ± o-oio 



Postclypeus length (Pel) . . 0-23-0-25 0-240^0-011 



Antennal article III . . . 004-005 0047 ± 0003 



Antennal article IV . . 005-006 0051 ± 0004 



Antennal article V . . . 005-0-06 0-056 4j 0-004 

 Left mandible, apical to first 



marginal (La) • • • 0-11-0-12 0-115 ± 0-004 

 Left mandible, first to third 



marginal (Li) . . . 0-15-0-17 0-159 ± 0-007 

 Left mandible, third marginal to 



molar (L m ) .... 0-06-0-07 0068 4j 0-004 

 Right mandible, apical to first 



marginal (Ra) • • • 0-11-0-12 0-115 ± 0003 

 Right mandible, first to second 



marginal (Ri) . . . 0-11-0-12 0-113 ±0-003 

 Right mandible, second marginal 



to molar (R m ) • • • 0-07-0-08 0-074 ± 0-002 



Mesonotum width (M) . . 0-25-0-30 0-269 ± 0-019 



Metanotum width (N) . . 0-26-0-30 0-275 ± 0-018 



Worker. Head capsule pale yellow, pilosity rather sparse but strong and conspicuous, 

 yellow. Postclypeus moderately inflated, Pcl/W, 0-25-0-29, Pcl/Ri, 2-00-2-34. Apical teeth 

 of mandibles long, La/Li, 0-80-0-88, Ra/Ri, 1-04-1-10; subsidiary marginal tooth of left man- 

 dible just clear of molar prominence in surface view, La/Li. Lm, 16-42-18-61 ; first marginal tooth 

 of right mandible distinctly behind line of apical to second marginal, anterior edge of first 

 marginal shorter than that of second, Ra/Ri-Ruu 17-30-21-90. Fore tibia slender, Ti/T w , 

 5-06-5-75, third apical spur distinct, about half length of other two. Mesenteric overlap with 

 proctodeum about twice as long as width of mesenteron at insertion of malpighian tubules, 

 proctodeum reaching half-way through malpighian knot ; enteric valve seating ventrolateral in 

 unopened abdomen, rather weakly three-lobed, third lobe smaller, connected to second pouch 



