2. _Dentate_, when the joints are armed with slight pointed spines.

{xi}3. _Serrate_, when the joints have sharp projections like the teeth of

a saw. (Fig. 18, antenna of _Melanchra composita_.)

4. _Filiform_, when the whole antenna is simple or thread-like. (Fig. 19,

antenna of _Epirranthis alectoraria_.)