The Termites of South Africa 47 



Total length 4. 1 to 11 mm. 



Head width 0.88 to 1.9 mm. 



Head and mandibles . . 2.2 to 3.7 mm. 



There is a regular increase of about 0.10 mm. in the head 

 width as from 0.88 to 1.4 mm.; there is then a break of 0.20 

 mm., the largest ranging in head width from 1.6 to 1.9 mm. It 

 is only these few odd large soldiers of 9 to 11 mm. long that 

 could possibly be regarded as majors. I have found the right 

 mandible to be regularly as long as the head is wide, but the head 

 length is variable as may be seen by the following contrasts: 



mm. mm. mm. mm. 



It is readily seen from this that some heads are visibly more 

 elongate-rectangular than others. To this it may be added that 

 the largest soldiers have the heads more regularly rectangular than 

 the lesser, and the sides straighter, some even faintly incurved. 



(c) An examination of many soldier mandibles shows consid- 

 erable differences. In the larger soldiers these organs are broader 

 and coarser than in the smaller. Apart from this all mandibles 

 differ extremely, both left and right, as regards the dental arma- 

 ture. Generally speaking, the teeth of the mandibles of the smaller 

 soldiers are more acute and more antrose than those of the larger 

 soldiers, but this does not hold good for all. The right mandible 

 always exhibits a large step-like tooth below its arcuate, apical 

 point; below this tooth there may be 2 or 3 quite distinct sub- 

 triangular teeth, or there may be an irregular series of knob-like 

 teeth; any one of these may have a simple rounded apex or a 

 notched apex. In one mandible I have noted three pointed teeth, 

 and below these two knobbed teeth, giving six teeth to the right 

 mandible. A suggestion of an extra tooth is often to be found 

 on the cutting edge of the apical point. Scarcely two right 

 mandibles are to be found that are quite alike. 



