POLYRIIACIIIS. 397 



Polvrhixcliis argenteus, MayrJ'crli. ~ool.-f)ot. (jCx. Wien, xii (ls(;2), 



Polyrhachis oalipata, Emenf, A^di. Mv^. C/r. Coi. xxxiv (1804), 

 p. 482. ^ . 



^ . Black ; the legs more or less castaneous red ; the whole 

 insect covered with a fine dense, recumbent, silky silvery pile, very 

 brilliant and glittering in fresh specimens, and entirely hiding the 

 sculpture. Head very conA^ex in front and at the sides ; elypeus 

 tectiform, its anterior margin more or less rounded. Thorax 

 convex, sometimes with the meso- and pronotum gibbous ; pronotal 

 spines short, acute, pointing forwards ; metanotal spines straight, 

 pointing backwards, and with a more or less distinct ridge between 

 them across the metanotum ; legs long and slender, the tibiae 

 smooth. Node of pedicel high, biconvex, the middle slightly 

 arched, bearing two short teeth, the lateral angles spined, the 

 spines wide-spreading, curved to the shape of the abdomen. 



2 . Similar, more massive ; the thoracic and pedicel spines 

 shorter and thicker, the pronotal spines being reduced to mere 

 acute tubercles ; abdomen very massive ; wings brown, nervures 

 darker. 



Lenfjth, g 4-5*o ; 5 6'5 mm. 



Hah. India, Kanara (Wrou(/htO)i). Bengal {Rotlmey) ; Ceylon 

 ( Yerburi/, Green) : Burma ; Tenasserim {Bingham) ; extending to 

 the Malayan subregion. 



The convexity of the thorax varies very much in this species, and 

 cannot be relied on as separating fibialis from acasta. 



47 ! . Polyrhachis chalybea, Smi'tli, Jonr. Limi. S»c. ii (1857), p. 61, ^ ; 

 Ford, Jovr. liomh. N. H. Soc. viii (1803), p. 1>3, 9 . 



^ . Head, thorax and node of pedicel black, legs and abdomen 

 brilliant metallic purple; head, pro- and mesothorax finely rugulose, 

 opaque, metathorax and node of pedicel polished, shining; abdomen 

 smooth, brilliant and glittering. Head oval, constricted posteriorly. 

 Thorax elongate : pro- and mesothorax of about equal width ; the 

 mesonotum circular, very slightly convex above ; pronotal spines 

 slender, acute, suberect, pointing slightly forwards ; metathorax 

 laterally strongly compressed, above concave, the sides vertical ; 

 the metanotal spines erect, nearly vertical, with very broad bases ; 

 legs stout, elongate ; tibiae minutely and sparsely spinose beneath. 

 Node of the pedicel cubical, flat and truncate anteriorly, the 

 posterior lateral angles with stout spines erect, slightly curved 

 downward ; abdomen short, very convex. 



Lenrjth, ^ 9-10 mm. 



Hah. Mergui and soutlnAards in Tenasserim (Binr/ham) ; 

 Malacca ; Borneo. 



472. Polyrhachis abdominalis, Smif/i, Cat. \i (1858), p. (i;;, g ; Forel, 

 Jour. Bomh. N. II. Soc viii (l8i)3), p. 24. ^. 

 Polyrachis phyllophiliis, Smith, Jour. Liini. Soc. v (ISlllj, p. 69. g. 



