THE AX ATOMY OF INSECTS. 



II 



In descriptive works names have been given to particular parts of the anten- 

 nae, as follows (Fig. 20) : 



The Scape. — The first or proximal segment of an antenna is called the scape 

 (a). The proximal end of this segment is often 

 £ ..-'--., subglobose, appearing like a distinct segment ; in 



such cases it is called the bulb. 



The Pedicel. — The pedicel (b) is the second 

 segmentof an antenna. In some insects it differs 

 greatly in form from the other segments. 



The Cldvola. — The term clavola (c) is applied 



to that part of the antenna distad of the pedicel ; 



in other words, to all of the antenna except the 



In some insects certain parts of the clavola are 



These are the ring-joints, the 



Fig. 20. — Antenna of Chalcis-fly. 



first and second segments. 



specialized and have received particular names. 



funicle, and the club. 



The Ring-joints. — In certain insects {e.g., Chalcididae) the proximal segment 

 or segments of the clavola are much shorter than the succeeding segments ; in 

 such cases they have received the name of ring-joints (V 1 ). 



The Club. — In many insects the distal segments of the antennae are more or 

 less enlarged. In such cases they are termed the club (c 3 ). 



The Funicle. — The funicle (V") is that part of the clavola between the club 

 and the ring-joints ; or, when the latter are not 

 specialized, between the club and the pedicel. 



The various forms of antennae are designated by 

 special terms. The more common of these forms 

 are represented in Fig. 21. They are as follows: 



1. Setaceous or bristle-like, in which the seg- 

 ments are successively smaller and smaller, the 

 whole organ tapering to a point. 



2. Filiform or thread-like, in which the seg- 

 ments are of nearly uniform thickness. 



3. Moniliform or necklace-form, in which the 

 segments are more or less globose, suggesting a 

 string of beads. 



4. Serrate or saw-like, in which the segments are 

 triangular and project like the teeth of a saw. 



5. Pectinate or comb-like, in which the segments 

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

 comb. 



6. Cldvate or club-shaped, in which the segments 

 become gradually broader, so that the whole organ 

 assumes the form of a club. 



7. Capitate or with a head, in which the terminal segment or segments form 

 a large knob. 



8. Lamellate, in which the segments that compose the knob are extended 

 on one side into broad plates. 



Fig. ax. — Various forms of an- 

 tennae. 



