250 
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 antennas of beetles. 1, serrate; 2, pectinate; 3, cap¬ 
itate (and also elbowed); 4-7, clavate; 8-9, lamellate; 10, serrate; 11, 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 
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 logs, on or in decaying matter, in fresh water, etc., 
