POLYRHAC'HIS. 



383 



$ . Similar to the . Thorax subovate and more massive. 

 As a rule the armature is similar, but the thoracic and pedicel 

 spines or teeth are generally shorter and^thicker. Fore wing with 

 one marginal and two cubital cells, the*2nd cubital cell generally 

 reaching the outer margin of the wing. Abdomen larger than in 

 the , with the basal segment proportionately not so long. 



c? . Similar to the $ , but very much smaller, with a narrower 

 abdomen, and in all the species of which the males are known with 

 the thorax and node of the pedicel unarmed. 



The species of Polyrhachis are on the whole arboreal ants, making 

 their nests either between the leaves or in the hollows of trees 

 and bamboos. A few P. Icevissima, Smith, for instance nest in 

 the ground ; others like P. armata, le Gruillou, occasionally make 

 their nests inside human habitations. The nests of Polyrhachis 

 are of a silky cobwebby material, which, when the nests are made 

 among leaves, is used to attach leaf to leaf ; in ground-building 

 species it is used to line the galleries. P. armata, P. dives, and 

 many others construct the whole nest of this material. 



Kei/ to ilie Species. 



A. Thorax and pedicel armed with spines or teeth, 

 a. Thorax more or less rounded above, the sides 



not margined along their whole length. 

 a'. Pro- and mesonotum with a spine on each 



side. 

 a~. Spines on node of pedicel parallel for a 



part of their length from base. 

 a 3 . Pronotal spines pointing outwards, 

 and curved laterally backwards, 



forming hooks P. bihamata, p. 380. 



b 3 . Pronotal spines pointing outwards, 

 slightly bent downwards, not forming 



hooks P. bellicosa, p. 387. 



6 2 . Spines on node of pedicel not parallel, 



divergent from base ^ P. ypsilon, p. 387. 



b'. Pro- and metanotum with a spine on each 



side, mesonotum unarmed. 

 a 2 . Pubescence soft, erect and abundant. 

 3 . Spines on node of pedicel forming 



hooks P.fwrcttta, p. 388. 



b 3 . Spines on node of pedicel not forming 



hooks. 



a 1 . Head not punctured, smooth, shining. P. yracUior, p. 388. 

 b*. Head coarsely punctured posteriorly. P. phipsoni, p. 889. 

 b\ Pubescence short', silky and recumbent, 

 or sparse and erect, or entirely absent. 

 a n . Metanotal spines forming hooks. 



a*. Abdomen with dense golden pile . . P. mj>icaj)ra,Tp.3SU. 

 b*. Abdomen without pile or pubescence. 

 a 5 . Thorax finely punctured, head and 



nbdomen opaque P. hodysoni, p. .'{90. 



&'. Thorax coarsely punctured, head 



and abdomen shming P. nrackne, p. 390. 



