188 INSECTS. 



This peculiarity in the Bees will be further noticed in 

 its own place. 



Subsection 1. PR&DONES. The Praedones (Prcedo, 

 a robber) form three Divisions 1. Heterogyna, con- 

 taining the Ants; 2. Fossores (Fossor, a digger), 

 containing the Sandwasps ; 3. Diploptera, containing 

 the true Wasps. The two first are easily distinguished 

 from the third, which has the fore-wings folded length- 



Fig. 53. 



Outline of Formica. 



ways ivhen at rest (whence the name AtTrXow, diploo, to 

 double; wrepov, a wing). The other two divisions are 

 less easy to distinguish from each other, but the fol- 

 lowing rules may be sufficient. Heterogyna consists of 

 the Social Ants and of the Solitary Ants. The Social 

 Ants may be distinguished from the Sandwasps by the 

 form of the footstalk by which the abdomen is attached to 

 the thorax, and which forms, in some, one scale-like 

 projection (fig. 53), or a knot-like lump ; in others 

 (fig. 54), two such lumps or nodes. 



The Solitary Ants may be distinguished from the 

 Sandwasps by the female of the former being always 

 wingless, while the male is generally toothed or spired at 

 the apex of the abdomen. 



When, therefore, an insect has been shown by the legs 

 to belong to the subsection PR^DONES, and by its non- 



