12 



COLEOPTEEA OF INDIANA. 



which the rinteniuv end in an abrupt ehil) the pores are confined to 

 its surface ; in most cases, however, they are generally scattered 

 over all except the basal joints. 



The principal forms of antenna' are as follows: 



(a) Filiform or thread-like, where the joints are cylindrical 

 and the outer ones not or scarcely enlarged. 



(h) Seiaceous or liristle-like, where the joints are fjradually 

 more slender to the tip. 



(c) CapiUarj; or hair-like, wliere tlie joints are lonp;, slender 

 and verv loosely united. 



/:r>=^-^=«<113 



Fig. 3. Serrate antenna and modifications: 1, serrate; 2, pectinate; 3, bipcctinate; 4, flabellate; 

 5, plumose; 6, 7, 8, irregularly serrate. (After LeConte and Horn.) 



(d) Mo)iiJifor)i) or l)ead-like, Avhen the joints are of nearly 

 uniform size and rounded, thus resemblinp; a string of beads. 



(e) Serrate or saw-like, when the joints are triangular and 

 compressed, presenting therefore a saw-tooth-like outline on the 

 front margin. 



if) I'ccfiiKife or comli-like. when the joints are short, with 

 their front angles much prolonged. 



(g) Bipeetinate, when each joint has a comb-like tooth on each 

 side. 



{h) FlaheUate or fan-like, when \\\o prolongations from the 

 joints are very long compared with the antenna', and fold together 

 like a fan. 



(/) • Plumose or feather-like, when the prolongations are long, 

 slender and flexible. 



(,/') CUavafe or c]ul)-like, where the outer joints are more or 

 less enlarged, ])ut not triangular or leaf-like. This is among beetles 

 the most common form of antenna', and it grades gradually into 

 most of the other types. 



