142 HYMENOPTERA. 



rule, as exemplified in the aculeate Hymenoptera ; thus the nor- 

 mal number of joints in the antennae of the females being 12, 

 and 13 in the males, as a general rule, serves to discriminate the 

 sexes : the workers also have usually 12-jointed antennae, but in 

 the present genus both the female and worker have only 7 joints. 

 The genus Orectognathus has only 5 joints in the antennae, but 

 only wcrkers are known. In Heptacondylus, however, the female 

 has the s.ime reduced number of joints as the worker, and this 

 must be considered the perfect condition of the species. 



1. Heptacondylus subcarinatus. B.M. 



Worker. Length 2^ lines. — Head, antennae, thorax and legs, 

 ferruginous, or pale ferruginous ; abdomen fuscous, or rufo-fus- 

 cous, the ])etiole of the basal node pale ; head shinmg, and having 

 a number of short, irregular, delicate carinae on the front and 

 vertex ; there are also a few irrregular striae in front of the eyes. 

 Thorax : the sides compressed, widest in front, the superior sur- 

 face slightly convex, and having a number of longitudinal, abbre- 

 viated, slightly elevated carinae, the lateral margins traversed by 

 a slight carina ; the metathorax with two stout acute spines. 

 Abdomen smooth and shining ; the insect sprinkled with a num- 

 ber of pale erect hairs, most numerous on the antennae and legs. 



Hab. Borneo (Sarawak). 



2. Heptacondylus carinatus. B.M. 



Worker. Length 2| lines. — Dark fusco-ferruginous : closely 

 resembling H. subcarinatus, but with thicker antennae and the 

 joints shorter; the scape distinctly shorter, and not so slender at 

 the base ; the head proportionately larger, and much more 

 strongly carinated ; the thorax roughly carinated, and having 

 longer and stouter spines ; in other respects resembling H. sub- 

 carinatus. 



Hab. Borneo (Sarawak). 



Whether this can possibly be a form of H. subcarinatus, it is 

 impossible to determine ; the various differences pointed out ap- 

 pear to distinguish a distinct species. 



3. Heptacondylus longipes. B.M. 



Worker. Length 2f lines. — Dark rufo-fuscous : the antennae, 

 head beneath, mandibles and lower part of the face, ])ale rufo- 

 testaceous ; antennae much more slender and elongate than either 

 of the preceding species. Head smooth and shining, not cari- 

 nated. Thorax smooth and shining, the lateral margins traversed 



