POLYRHACHIS. 397 



Polyrhachis argenteus, Mayr,Ver1i. zool-bot. Ges. Wicn. xii 



p. 682, . ' 

 Polyrhachis cali^ata, Emery, Ann. Mm. Civ. Gen. xxxiv (1894), 



p.488,g. 



. 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 convex in front and at the sides ; clypeus 

 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. 



Length, 4-5*5 ; $ 6*5 mm. 



Hob. India, Kanara (Wrouc/hton), Bengal (Sothney) ; Ceylon 

 (Yerbury, 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 tibialis from acasta. 



47 1 . Polyrhachis chalybea, Smith, Jour. Linn. Soc. ii (1857), p. 61, $ ; 

 For el, Jour. Bomb. N. H. Soc. viii (1893), p. L>3, $ . 



5 . 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. 



Length, $ 9-10 mm. 



Hab. Mergui and southwards in Tenasserim (Bingham} ; 

 Malacca ; Borneo. 



47->. Polyrhachis abdoininalis, Smith, Cat. vi (1858), p. 68, $ ; Furel, 



Jour. Bomb. N. H. Soc. viii (1898), p. 24, $. 

 Polvrachis phyllophilns, Smith, Jour. Linn. Soc. v (1801), p. 69, $. 



