2 5 



Beetles 



organs of flight; the firm, thick, usually dark, chitinized cuticle or outer 

 body-wall; the strong-jawed biting mouth, and the compact body, usually 

 short and robust, are structural characteristics obvious and usually dis- 



FIG. 340. The different forms of antennae of beetles, i, serrate; 2, pectinate; 3, cap- 

 itate (and also elbowed); 4-7, clavate; 8-9, lamellate; 10, serrate; n, irregular 

 (Gyrinus); 12, 2-segmented antennae of Adranes cacus. (After LeConte.) 



tinctive. Especially used in classification are the differences in number 

 of tarsal segments of the feet, and differences in the character of the antennae. 

 To learn the range of these differences in the antennae, and the names applied 

 to the various kinds a careful inspection of Fig. 340 will do more than a 



FIG. 341. Different forms of legs and tarsi of beetles. (After LeConte and Comstock.) 



page of description. Similarly Fig. 341 illustrates the range of the charac- 

 ters drawn from the tarsi. 



The development of beetles is "with complete metamorphosis "; that is, 

 from the eggs laid underground, or on leaves or twigs, in branches or trunks 

 of live trees, in fallen legs, on or in decaying matter, in fresh water, etc. : 



