1897.] of the Goleoptera of South Africa. 5 



received at the Museum have always been caught coming to the lights 

 in houses or at the camp fire. This is also the case with Pleuropterus 

 (two kinds) and other Paussus ; and the specimens thus caught are 

 mostly males. 



However, because these insects are found in ants' nests, it does 

 not follow that they are of use to the ants in the way that Aphidoe, 

 are, and Clavigeridcz are said to be. I have kept in captivity for a 

 lengthy period a good many examples of three Paussi (P. Burmeisteri, 

 P. Limiei, and P. lineatus) as well as Pentaplatarthrus paussoides, 

 and I never saw the ants attending to them at all. The Paussi are 

 carnivorous and are feeding on the young larvae, but rather than 

 drag them away by force, the nurses prefer removing the heap of 

 larvae and eggs from their reach. 



I have suggested (Proc. Entom. Soc, Lond., 1886, p. xxxvi) that 

 either the crepitating power of the beetle is so well known to the 

 ants that they make a virtue of necessity, or that they are so much 

 accustomed to- the presence of Paussi in their colonies through 

 hereditary consciousness of that crepitating power that they no 

 longer struggle against the intruders. This latter view, if correct, 

 seems to go far in explaining why so many species of Paussi are 

 found in the nests of ants belonging to the genus Pheidole* 



It might be objected that Paussi kept under unusual conditions in 

 an artificial formicarium might adapt themselves to the conditions 

 obtaining therein and devour the larvae for want of the ordinary 

 staple food, but the appetite of the examples under my observation 

 was as keen when introduced into the formicarium as later on. I 

 have in two instances caught Paussus munching away ants' larvae 

 in ants' ?iests. 



The anatomy of the buccal organs shows, I think, unmistakably that 

 the diet of the Paussi must consist of something soft ; the mandibles 

 are, it is true, long, sharp, and more or less falcate at tip, but this is 

 not so much for the purpose of seizing the prey as of use for mating. 

 It is by means of these organs that the male catches hold of the 

 discoidal cavity in the prothorax of the female, and the small pads 

 of flavescent hairs which, I believe, are alio ays present in fresh 

 examples of the genus Paussus, are also probably connected with 

 copulating purposes. The jaws (maxillce) are decidedly feeble, the 

 internal lobe is seldom set with rigid spines, and they are, as a rule, 

 deeply incised, or bifid) and eminently adapted for slow manducation 

 accompanied by suction, such as I found to be the case with the 



* Paussus Favieri, one of the two European species, and occurring in Southern 

 France, Spain, and Algeria, is also found in the nests of a Pheidole, P. megace- 

 phala ; and the other, P. turcicus, with Pheidole pallidula. 



