HYMENOPTERA. 25 



emarginate. Thorax usually more or less fuscous in front, com- 

 pressed behind. Abdomen shining, the apical margins of the 

 segments narrowly testaceous ; the scale of the peduncle ovate 

 and ferruginous. 

 Hab. Borneo (Sarawak). (Coll.W. W. Saunders, Esq.) 



85. FORMICA IRRITABILIS. B.M. 



Worker. Length 4 lines. Head, thorax, and scale of the 

 abdomen, ferruginous, the legs rufo-fuscous ; abdomen nearly 

 black ; the scape black, with the extreme base and apex as well 

 as the flagellum ferruginous, the latter more or less fuscous 

 above ; the vertex has sometimes a fuscous stain ; the mandibles 

 nigro-piceous, their apex ferruginous. Thorax compressed 

 behind, much narrower than the head, both thinly sprinkled with 

 erect reddish hairs ; the legs nigro-fuscous, with the base and 

 apex of the joints, and sometimes with the coxa3 and apical joints 

 of the tarsi, ferruginous. Abdomen : the scale oblong- ovate, 

 pointed above ; the apical margins of the segments with a thin 

 fringe of reddish-yellow hairs. 



Hab. Borneo (Sarawak). 



86. FORMICA SEDULA. 



Worker. Length 5 lines. Head and thorax opake-black, 

 the mandibles and legs shining black ; the abdomen chestnut- 

 red. The mandibles with five stout teeth, and with their apex 

 striated ; the head much wider than the thorax, deeply emar- 

 ginate behind; the flagellum obscurely ferruginous. Thorax 

 compressed behind; the trochanters and apical joints of the 

 tarsi ferruginous. Abdomen ovate ; the scale of the peduncle 

 subquadrate, slightly emarginate above; the abdomen thinly 

 sprinkled with reddish pubescence, and a few scattered black 

 hairs on the head and thorax. 

 Hab. Borneo (Sarawak). (Coll. W. W. Saunders, Esq.) 



87. FORMICA EXASPERATA. 



Worker. Length 5| lines. Head, thorax, and scale of the 

 peduncle, blood-red, the abdomen black ; a dark stain in front 

 of the anterior stemma, and usually a second at the insertion of 

 the antennae; these stains sometimes obsolete; the mandibles 

 black, stout, punctured and strongly toothed ; the head much 

 wider than the thorax and deeply emarginate behind. Thorax 

 compressed behind, usually more or less stained at the sides ; 

 the tibise and tarsi more or less fuscous. Abdomen with the 



c 



/ 



