POLTBHA.CHIS. 399 



474. PolyrhacMs mutata, Smith, Cat: vi (1858), p. 64, pi. iv. figs. 12, 



13, . 



Polyrachis mutata, Smith, race ajax, Forel, Jour. Bomb. N. H. Soc. 

 viii (1893), pp. 24 & 32, . 



. Resembles P. abdominalis, Smith, but is more slenderly made, 

 with the thorax much narrower and the thoracic and pedicel spines 

 longer and more slender. Black, the abdomen from a brownish 

 black or dark brown to dark red. Head, thorax and abdomen 

 minutely rugulose granulate and opaque, 

 the abdomen more minutely rugulose than 

 the head and thorax ; pilosity extremely 

 sparse, confined to the extremities of the 

 head and abdomen ; pubescence extremely 



v IQA T> i i i- thin and minute, visible only in certain 

 .big. IJb. Poh/rhactns ,. . , TT , .' , ,. J . 



mutata, Thorax. lights. Head with the posterior portion 

 retreating and only lightly convex, the 



sides nearly straight; the eyes prominent, placed above the middle 

 and rather forward ; mandibles broad and powerful, armed with 5 

 teeth, finely striate towards the apical margin ; clypeus nearly flat, 

 very indistinctly subcariuate down the middle ; antenna long and 

 slender, the scape extending more than half its own length beyond 

 the top of the head. Thorax : the pro- and metanotal spines very 

 long, almost horizontal and level with the back, divergent forward 

 and backward respectively, the pronotal spines slightly curved 

 downwards ; pronotum between the spines flat ; mesonotuin slightly 

 longitudinally concave, strongly margined ; metanotum very 

 narrow, concave from side to side and laterally margined, the 

 margins in a line with the base of the metanotal spines; legs long, 

 the tibiae remarkably compressed and flattened, with a row of short 

 but distinct spines on their internal margin. Pedicel thick, cylin- 

 drical, truncate posteriorly, and armed with two long divergent 

 spines curved to the abdomen, not so slender as the metanotal 

 spines ; abdomen subglobose. 



Length, $ 7-8 mm. 



Hab. Burma : Pegu Yoma, Maymyo, 3000 feet ; Tenasserim 

 (Bingliam). 



It is somewhat doubtfully that I join the race ajax, Forel, 

 with mutata, Smith. Though originally collected by myself, I have 

 now only one mutilated specimen of P. ajax named by Dr. Forel. 

 This latter seems to me smaller, with a proportionately shorter, 

 broader bead and thorax than typical P. mutata, Smith, which I 

 got plentifully at Maymyo. 



475. Polyrhachis binghami, Forel, Jour. Bomb. N. H. Soc. viii (1893), 



pp. 25 & 33, . 



$ . Closely resembles P. mutata, Smith, especially the race ajax, 

 Eorel, but is 'a smaller and more stoutly built insect, entirely black 

 and slightly more coarsely granulate. Head somewhat short-er and 

 squarer ; clypeus slightly more convex ; pronotal spines shorter, 

 stouter and straighter, not curved; mesonotum transversely convex, 



