SMITH ON HYMENOPTEEA OF AEU ISLANDS. 139 



'13. Formica angulata. F. nigra nitida; flagello capite antice pe- 

 dibusque obscure ferrugineis, mctathorace angulato. 

 M'^orker. Length 3 lines. Shining black ; head of moderate size ; the 

 clypeus and mandibles obscure ferruginous ; the flagellum fusco-fer- 

 ruginous, with the tip pale testaceous. Thorax rounded anteriorly 

 and compressed behind ; the scutellum prominent, forming a small 

 tubercle ; the metathorax obliquely truncate, the margin of the trun- 

 cation elevated, so that when viewed sideways the metathorax forms 

 an obtuse angular shape. Abdomen ovate, the node of the peduncle 

 elevated, incrassate, rounded anteriorly, and flat behind. 

 Hab. Aru. 



Gen. PoLYEHACHis, Smith. 



1. Formica sericata, Guer. Voy. Coq. Zool. ii. 203; Atlas Ins. pi. 8. 

 f. 2, 2 a, b, c, d, ^ . (Polyrhachis sericata. Smith, Append. Cat. 

 Form. p. 200.) 



Hab. Aru ; New Hebrides. 



2. Formica sexspinosa, Latr, Hist. Nat. Fourm. p. 126, pi. iv. f. 21 ^ . 

 (Polyrhachis sexspinosa. Smith, Cat. Form. p. 56. 3.) 



Hab. Aru ; India ; Philippine Islands. 



3. Polyrhachis marginatus. P. niger; antennis, palpis pedi- 

 busque ferrugineis ; thoracis marginibus recurvis, metathorace peti- 

 olique squamula bidentatis. 



Worker. Length 2^ lines. Black ; the antennae and legs ferruginous ; 

 the head and thorax rugose; the prothorax transverse, its anterior 

 margin slightly curved, with the lateral angles produced forwards and 

 very acute ; the thorax narrowed to the metathorax, which is armed 

 with two divergent acute spines. Abdomen velvety black and glo- 

 bose ; the scale of the petiole produced laterally into long, bent, acute 

 spines, which curve backwards to the shape of the abdomen. 



Hab. Aru. 



4. Polyrhachis hostilis. P. niger, longitudinaliter striatus, tho- 

 racis marginibus expansis, metathorace squamulaque petioli spinis 

 duabus crassis acutis curvatis. 



Worker. Length 3 lines. Black ; the head and thorax longitudinally 

 striated, the abdomen very finely and evenly so ; the prothorax trans- 

 verse, wider than the head, the anterior and lateral margins recurved, 

 the latter acute at their anterior angles, and rounded at the posterior 

 ones ; the lateral margins of the mesothorax recurved, a deep notch 

 between the meso- and metathorax ; the latter with a long, stout, 

 curved, acute spine on each side. The scale of the petiole produced 

 above on each side, into a long, curved, stout, acute spine, which 

 curves backwards round the sides of the abdomen. 



Hab. Aru. 



