542 Annals of the South African Museum. 



placed at the middle of the sides. Thorax long and narrow. The 

 sides and front of the pronotum subvertical. Pro-mesonotal suture 

 feeble in the smaller $ £ , more distinct in the larger $ £ , in which 

 the mesonotum is somewhat tumid in front and clearly higher than 

 the level of the pronotum. Declivity of the mesonotum short and 

 oblicpie in the small $ ^ , longer and steeper in the larger $ $ . Meso- 

 epinotal suture not deep ; mesopleura feebly reticulate. Median 

 tubercle of the mesonotum obsolete or nearly so. Dorsum of epinotum 

 merging into the declivity by a very gradual curve, armed with two 

 very short, suberect teeth, which are shorter than their basal width. 

 First segment of petiole trapezoidal, a little longer than wide in front, 

 the anterior angles widely rounded. Node of 2nd segment feebly 

 emarginate behind and shallowly grooved longitudinally above, not so 

 wide as the 1st segment. Abdomen elongate, two-thirds longer than 

 wide. 



Q minor 



Fig. 53. — C. nigronitens, Santsclii. 



Matoppo Hills, S. Rhodesia; nesting in the hollow and dead 

 branches of a small shrub. 



A very distinct species, easily recognised by its polished integu- 

 ment, elongate head, short scapes and minute epinotal teeth. 



Sub-genus OXYGYNE, Forel. 

 Ann. Soc. Ent. Belg., vol. 45, p. 376, 1901. 



" Distinguished in the $ by the more or less completely edentate 

 mandibles which lack a masticatory margin ; by the rudimentary 

 frontal carinae and by the aberrant and characteristic structure, 

 whereas in the 9 $ of Cremastogaster, s. str., the structure varies but 

 little and is not very characteristic of the species." Type of sub-genus, 

 C. Emmae, Forel. In C. Daisyi, Forel, the £ £' also have no frontal 

 carinae, and the mandibles are 4-dentate and very narrow, the epinotum 

 with long spines, antennae 11-jointed. 



In some species the £ £ have the epinotum unarmed, and the 

 frontal carinae are sometimes fairly developed, so that the characters 

 diagnostic for the sub-genus appear as yet to be insufficiently deter- 

 mined for the $ caste. 



