6o 



THE STUDY OF INSECTS. 



The various forms of antennae are designated by special 

 terms. The more common of these forms are represented 

 in Figure 74. These are as follows : 



1. Setaceous (se-ta'ceous) or bris- 

 tle-like, in which the segments are 

 successively smaller and smaller, the 

 whole organ tapering to a point. 



2. Filiform (fiTi-form) or thread- 

 like, in which each segment is of 

 nearly uniform thickness throughout 

 its length; and the antenna as a 

 whole tapers gradually, if at all, to- 

 wards the tip. 



3. Moniliform (mo-nil'i-form) or 

 necklace-form, in which the segments 

 are more or less globose, suggesting 

 a string of beads. 



4. Serrate (ser'rate) or saw-like, 

 in which the segments are triangular, 



FIG. 74. Various forms of an- 

 tennae. an d project like the teeth of a saw. 



5. Pectinate (pec'ti-nate) or comb-like, in which the seg- 

 ments have long processes on one side, like the teeth of a 

 comb, or on both sides, like a feather. 



6. Clavate (cla'vate) or club-shaped, in which the seg- 

 ments become gradually broader, so that the whole organ 

 assumes the form of a club. 



7. Capitate (cap'i-tate) or with a head, in which the 

 terminal segment or segments form a large knob. 



8. Lamellate (Jam'el-late), in which the segments that 

 compose the knob are extended on one side into broad 

 plates. 



TJie Mouth-parts. No set of organs in the body of an in- 

 sect vary in form to a greater degree than do the mouth-parts. 

 Thus with some the mouth is formed for biting, while with 

 others it is formed for sucking. Among the biting insects 

 some are predaceous, and have jaws fitted for seizing and 



