POLYBHACHJS. 413 



4!) 7. Polyrhachis halidayi, Emery, Ann. Mm. Civ. Gen. xxvii (1887), 

 p. 517, $ ; Forel, Jour. Bomb. N. H. Soc. viii (1893), p. 19, $ . 



. Resembles P. dypeata, Mayr, but is larger and more robust 

 and the sculpture is entirely different. Black, the mandibles 

 and legs castaneous red, the latter more or less shaded with 

 fuscous ; head and thorax neatly longitudinally striate ; node of 

 pedicel faintly and rather irregularly striate ; abdomen smooth and 

 shining, not opaque ; pilosity very sparse, recumbent pubescence 

 fine, thin, sericeous and shining. Head comparatively shorter 

 and, seen from in front, rounder than in P. dypeata ; clypeus 

 more convex and much more strongly carinate, anteriorly produced 

 into a rectangular lobe as in P. dypeata, but the anterior margin, 

 though transverse, is not dentate. Thorax broad in front, narrow 

 posteriorly, the pro-mesonotal suture broad and deep, the meso- 

 metanotal suture marked by a transverse carina ; the pronotum 



Fig. 144. Polyrhachis halidayi, $. 



angular laterally; the basal portion of the metanotum flat, not 

 concave, the teeth or spines at the posterior lateral angles minute ; 

 apical portion of metanotum concave, shining, very minutely 

 transversely striate; legs robust, tibiae smooth, not spined. Node 

 of pedicel biconvex, thicker than in P. dypeata, and quadrispinous 

 as in that species, but the lateral spines are broader and placed 

 higher up on the node, and the two medial spines are reduced to 

 obtuse teeth and placed much closer together ; abdomen broadly 

 oval. 



$ . Very similar to the g , the stria) on the head and thorax 

 coarser, the pronotum laterally obtusely angled ; the basal portion 

 of the metanotum transversely rectangular, its posterior margin 

 widely emarginate, the lateral angles slightly turned up ; the 

 abdomen longer and more massive ; the soft fine sericeous recum- 

 bent pile much denser, especially on the abdomen, and of a reddish 

 yellow. 



Length, $ 6-7 ; $ 8 mm. 



