COLLECTED IN BOENEO, ETC. 55 



10. Formica DiLiGENS. F. obscure rufo-picea ; antennis, mandibulis, 

 thorace subtus et lateribus, metathorace pedibusque laete rufis ; ab- 

 domine subtus pallide rufo-testaceo. 



Female. Length 9 lines. Head shining, dark rufo-piceous ; the carina 

 at the insertion of the antennas, the antennae, the anterior margin of 

 the face and clypeus, and the mandibles, ferruginous. The thorax 



, and legs ferruginous, with the mesothorax above and the scutellum 

 dark rufo-piceous; wings subhyaline, the nervures and tegulse pale 

 ferruginous. Abdomen shining dark rufo-piceous, beneath pale rufo- 

 testaceous ; scale subquadrate, its superior margin slightly emarginate 

 its entire width. 



Hah. Malacca. 



This insect closely resembles the F. ligniperda. 



11. Formica irritans. F. capite abdomineque nigro-fuscis ; an- 

 tennis, thorace, abdomine, squamula pedibusque ferrugineis. 



Worker. Length 6 lines. Elongate and slender ; head ovate ; dark 

 fuscous; the apex of the scape and the flagellum ferruginous; the 

 clypeus and mandibles dark rufo-piceous. The thorax, scale of the 

 abdomen and the legs, ferruginous ; the thorax elongate, compressed, 

 with the prothorax very slightly dilated at the sides. The scale of the 

 abdomen incrassate, rounded anteriorly and truncate behind. Ab- 

 domen ovate, nigro-fuscous ; the entire insect sprinkled with erect 

 pale hairs. 



Worker minor. Length 3 lines. Only differs in having the antennae 

 entirely pale ferruginous and the anterior legs stouter. 



Hab. Malacca ; Borneo (Sarawak). 



This is probably the worker of F. diligens. 



12. Formica fervens. F. capite abdomineque obscure rufo-piceis, 

 thorace pedibusque pallide ferrugineis. 



Worker. Length 4 lines. Head nigro-piceous, thorax and legs pale 

 ferruginous ; head subopake, with the mandibles and clypeus slightly 

 shining, the latter with scattered punctures ; the flagellum pale fer- 

 ruginous; the anterior margin of the clypeus slightly emarginate. 

 Thorax more or less fuscous in front, compressed behind. Abdo- 

 men black and shining, with the apical margins of the segments nar- 

 rowly testaceous ; thinly sprinkled with pale hairs ; the scale ovate 

 and ferruginous. 



Hab. Borneo (Sarawak). 



13. Formica gracilipes. F. ferruginea, abdomine (basi excepto) 

 obscure rufo-piceo. 



Worker. Length 2 lines. Pale ferruginous, abdomen dark rufo-piceous ; 

 antennae longer than the body ; head ovate, and wider than the tho- 

 rax, narrowed behind ; the eyes black and prominent. Thorax elon- 

 gate and compressed ; the prothorax narrowed into a slender neck ; 



