INTRODUCTION. 



IX 



The feelers (antenna) vary also in length ; sometimes not ex- 

 ceeding the breadth of the head, and sometimes much longer than 

 the length of the body. They are filiform (thread-like) when the 

 shaft is of equal thickness throughout the length, fig. 8 ; setiform 

 (bristle shaped), when it becomes thinner towards the point, fig. 9 ; 

 fusiform (spindle shaped), when it is thickest in the middle and 

 thin at the root and point, fig. 10; clavate (club form), fig. 1, a, 

 when it gradually thickens towards the summit, and capitate (knob 

 form), fig. 11, when it suddenly enlarges at the end. 



.8. 9. 



10. LL 



With regard to their covering, the antennae are either naked, or 

 finely or compactly ciliated, fig. 12, or furnished with two single 

 hairs on each segment, fig. 13, or tufted, fig. 14. 



Pig. 12. 



Fig. 13 



Kg. 14. 



The processes of the antennae are either in the form of obtuse 

 pyramidal teeth, fig. 15, or serrate, fig. 16, or pectinate, fig. 18. 



Pig. 15. 



Pig. 16. Kg. 17. Kg. 18. 



