HYMENOPTERA. 67 



with three elevated carinae in the middle, the antennae inserted 

 at the sides of the two outer ones ; the head rugose, the thorax 

 very coarsely so ; thorax not flattened above, armed with two 

 long, stout, acute spines in front and behind ; scale of the abdo- 

 men incrassate, armed above with two long, bent, divergent 

 spines. Abdomen smooth and shining, the entire insect sprinkled 

 with a few long pale hairs. 



Hab. Borneo (Sarawak). 



32. POLYRHACHIS CASTANEIVENTRIS. B.M. 



Female. Length 3i lines. Head and thorax black, and covered 

 with fine grey pubescence ; the antennae and legs ferruginous ; 

 the mandibles and palpi ferruginous ; the anterior coxae black, 

 the tarsi and posterior tibiae fuscous ; the thorax with two short 

 acute spines in front, and two similar spines on the metathorax 

 behind ; the peduncle black, quadrate, armed with two divergent 

 spines above. 



Var. Thorax castaneous, with a downy cinereous pubescence. 



Hab. Borneo (Sarawak). 



33. POLYRHACHIS VILLIPES. PI. IV. figs. 37, 38. B.M. 



Worker. Length 3f -4 lines. Black : the head and thorax 

 longitudinally delicately aciculate ; eyes ovate, very prominent, 

 situated high on the sides of the head, the head narrowed pos- 

 teriorly, the carinae much elevated on the face, the palpi pale 

 rufo-testaceous. Thorax armed in front with two long, acute, 

 divergent spines, not armed posteriorly; the superior surface 

 flattened, distinctly divided by two transverse sutures, and having 

 a curved decline to the verge of the truncation of the metathorax - 9 

 legs elongate, thinly covered with erect pubescence. Abdomen 

 smooth and shining, sprinkled with erect black hairs ; the pe- 

 duncle, viewed in front, subquadrate, narrowed to the base, the 

 superior lateral angles with long, stout, diverging, acute spines ; 

 there is also a minute spine at the side, a little beneath the 

 elongate ones. 



Hab. Borneo (Sarawak). 



34. POLYRHACHIS NITIDUS. B.M. 



Female. Length 4 lines. Jet-black : smooth and shining ; 

 thorax ovate, the metathorax with two long acute spines ; the 

 peduncle quadrate, armed with two, long, curved, acute spines ; 

 the thorax rounded anteriorly; the truncation of the metathorax 

 delicately transversely rugulose and shining ; the anterior tibiae 

 rufo-piceous in front ; wings subhyaline, faintly tinted with yel- 



