274 Annals of the South African Museum. 



broken up in parts and connected by transverse strands or 

 branches to form a more or less distinct network. 



sulcate = a sculpture composed of incised lines or fine grooves (not 

 common in South African ants). 



rugulose = a sculpture composed of very fine wavy lines. 



alutaceous = a sculpture composed of a very fine or microscopic 

 network. 



reticulate-punctate = a close and even puncturation, in which the 

 spaces between the punctures are not wider than the punctures 

 themselves, and form more or less of a network around them. 

 I have used the term as an equivalent of the German 

 " Fingerhutartig punktiert" (punctured like a thimble). 



The sense of such combinations as " striato-rugose," " rugoso- 

 striate " are sufficiently evident, and need no further comment. 



The genus Tetramorium is well represented in our regions, and is 

 composed of active species which generally nest in the ground. The 

 colonies are often large, and are in some cases known to harbour 

 many myrmecophilous insects. I have not, however, found any in 

 the nests of our Ehodesian species. 



I have thought it necessary to reduce Triglyphothrix, Forel, to the 

 rank of a sub-genus of Tetramorium, since there is not one character 

 or even a set of characters which can be used consistently as a basis 

 of differentiation. 



In Triglyphothrix Arnoldi, Forel, the hairs are simple as in 

 Tetramorium s. str. ; in Triglyphothrix Marleyi which has branched 

 hairs, there is no scrobe. Also no reliance can be placed on the 

 width of the nodes, which varies considerably. In the new species, 

 Tetramorium Ericae, the shape of the nodes and the general facies 

 of the insect is decidedly like that of Triglyphothrix, but the hairs 

 are simple, and the nodes only moderately wide, so that it might 

 just as well be assigned to that sub-genus as to Tetramorium. 



The sub-genera of Tetramorium may be distinguished as follows : 



1. $ and ? , antennae 12- jointed ; <J, antennae 10- jointed. 



(a) Hairs usually branched, or, if not, both nodes much wider than long, 

 the 1st node never squamiform . Triglyphothrix, Forel. 



(6) Hairs not branched; the 2nd node generally wider than long, or, if 

 both nodes are much wider than long, then the 1st is squamiform 



Tetramorium, Mayr. 



2. $ and ?, antennae 11- jointed; & , antennae 10- jointed. 



Xiphomyrmex, Forel. 



3. £ , ? i and <? , antennae 10- jointed . . . Decamorium, Forel. 



