170 Annals of the South African Museum. 



is taken along its ventral surface, where it is longest ; however it is 

 difficult at times to decide where the node ends and where the peduncle 

 begins. In these cases, the relative proportions of the two parts can 

 only be considered approximate. 



In Cremastogaster, there is no node in the strict sense of the term, 

 since the first joint of the petiole has the form of a very oblique 

 squame, the two faces of which are placed more or less dorsal and 

 ventral respectively, united to the epinotum by a very short and 

 narrow articular portion. 



In Myrmicaria $ , the node, which is more or less subconic, is very 

 sharply defined; it serves as a very good example to illustrate the 

 distinction between the two portions of the 1st joint. In Tetramorium 

 and some other genera, the node is often cuboid and furnished with a 

 more or less distinct peduncle. 



The 2nd joint is usually thicker in front than behind. It is also 

 generally narrower behind, but is never so much so as to form a 

 distinct peduncle attaching it to the abdomen. It varies less in shape 

 than the 1st joint. The ventral lamella of the 1st joint is not often 

 produced into a spine or tooth, as is so frequently the case in the 

 Ponerinae. 



The above remarks serve to show that the shape of the nodes cannot 

 often be described accurately in one word, and such expressions as 

 cuboid, conical, wedge-shaped, etc., must be understood as being only 

 approximate definitions. 



Key to the Genera of the Myrmicinae, <J> ^ • 



(2). 1. Clypeus not prolonged backwards between the frontal carinae, which. 



are placed more or less close together. Antennae 12-jointed. 



Sima, Roger. 

 (1). 2. Clypeus prolonged backwards between the frontal carinae, which are 



more or less widely separated. 

 (4). 3. Petiole attached to the dorsal surface of the abdomen. 



Cremastogaster, Lund. 

 (3). 4. Petiole attached to the basal apex of the abdomen, below the dorsal 



surface. 

 (10). 5. Head strongly cordiform, narrow in front, deeply emarginate behind, 



the posterior angles strongly rounded. 

 (9). 6. Antennae 6-jointed. 

 (8). 7. Antennal scrobe present ; head without spines ; a spongy mass covers 



the petiole, at least in part ; hairs spatulate . Strumigenys, Smith. 

 (7). 8. Antennal scrobe absent; head spined posteriorly; petiole without 



a spongy covering ; hairs simple . . Microdaceton, Santschi. 



(6). 9. Antennae 4-jointed ..... Epitritus, Emery. 

 (5). 10. Head not strongly cordiform, nor deeply emarginate behind. 



