166 HYMENOPTERA. 



than the head, slightly pubescent. Head enormously large, 

 shining, deeply emarginate behind, with a central longitudinal 

 channel, the face striated anteriorly ; the mandibles very stout, 

 their inner margin not toothed. Thorax rounded in front, nar- 

 rowed behind, and deeply strangulated between the raeso- and 

 metathorax, the latter with two minute acute spines. Abdomen 

 ovate. 



Female. Length 3} lines. — Fusco-ferruginous and shining : 

 the head ferruginous and longitudinally striated ; the legs and 

 antennae pale ; wings subhyaline and iridescent, the nervures pale 

 testaceous, the metathorax with two short acute spines. 



Hab. Port Natal. 



18. Atta spinoda. B.M. 



Female. Length 4 lines. — Black and shining, with the an- 

 tennae, mandibles, legs, head and thorax beneath, ferruginous ; 

 the vertex and the nodes of the peduncle obscure ferruginous ; 

 the head longitudinally striated. Thorax impunctate ; the me- 

 tathorax transversely striated, and armed with two short stout 

 acute spines. Abdomen elongate, with the apical margins of the 

 segments more or less rufo-piceous ; the second node of the pe- 

 duncle produced on each side into a short acute spine. 



Hab. Australia (Adelaide). 



19. Atta vigilans. B.M. 



Worker. Length 2 lines. — Ferruginous, with the abdomen 

 fuscous, and its base more or less pale. Head very largely de- 

 veloped, oblong, with a deep emargination behind, and a central 

 longitudinal channel extending to the clypeus ; the posterior half 

 of the head, the cly])eus and mandibles, smooth and shining, the 

 latter with a few scattered punctures ; the anterior margin of the 

 face and the inner margin of the mandibles blackish ; the an- 

 terior half of the face striated. Thorax smooth and shining; a 

 deep strangulation between the meso- and metathorax, the latter 

 with two short acute spines. Abdomen ovate and slightly pu- 

 bescent. 



Hab. Australia (Melbourne). 



20. Atta antipodum. B.M. 



Female. Length lines. — Black and shining : head small, 

 much narrower than the thorax, roughly punctured, running 

 into striae on the anterior portion of the face ; the mandibles 

 stout and strongly punctured ; the flagellum and legs ferrugi- 



