8 Annals of the South African Museum. 



The colonies are usually small in Ponerine ants, but may be very 

 numerous in some species, such as Palto thy reus tarsatus, Mega- 

 ponera foetens, Euponera sennaarensis, many species of Leptogenys 

 and Odontomachus haematoda. 



The habit of foraging in files has been observed in several species 

 of Ponerinae in different parts of the world. In our region this habit 

 is displayed by Megdponera foetens, and to a slight extent by Palto- 

 thyreus tarsatus. The former marches in double file, and the 

 striking disparity in size between the two forms composing the 

 colony has a very singular appearance. Their prey consists entirely 

 of termites, and when a suitable hunting-ground containing these 

 animals has been found, the columns break up and pour into every 

 hole and crack which leads to the invaded galleries. The method 

 then adopted is as follows : Each ant brings to the surface one or 

 more termites, and then re-enters the galleries to bring up more 

 victims. This is continued until each ant has retrieved about half a 

 dozen termites, which, in a maimed condition, are left struggling 

 feebly at the surface. The whole army reassembles again outside, 

 and each marauder picks up as many termites as it can conveniently 

 carry, usually 3 or 4. The columns are then re-formed and march 

 home. Less order is shown by P. tarsatus, but I have often seen 

 this ant carrying termites, in short single files composed of about a 

 dozen workers. 



According to my experience of the Ponerinae of Ehodesia, para- 

 sites and ant's-nest guests are remarkably scarce in the nests of 

 these ants. I have never met with any of the larger Paussidae 

 which are known or suspected to frequent their nests.* But in the 

 colonies of nearly all the Ponerinae, and in a large number belonging 

 to the other sub-families, a very common Thysanuran, of a slaty 

 colour, is found in abundance, and also a white Isopod. I have also 

 found in the nests of Platythrea cribrinodis a Cossyphodes (Arnoldi, 

 Brauns) in small numbers. 



Probably all the Ponerinae are able to make stridulatory sounds, 

 which in the case of the smaller species may be of so acute a pitch 

 as to be imperceptible to our ears. The stridulation is produced by 

 transverse striae on the under and upper surfaces respectively of the 

 1st and 2nd abdominal segments. In larger species, such as 

 Paltothyreus tarsatus and Megaponera foetens, the sound is plainly 

 audible at a distance of several feet. 



Other bionomic notes, when available, will be appended to the 



* Cerapterus natalensis has been found in the galleries of Platythyrea cribrinodis 

 in Natal. — The Editor. 



