46 



ZOOLOGT 



is composed of about ten thousand species, of extremely 

 varied form, size, and coloration. Most of them are of a 

 shiny black color, usually with longitudinal ridges or rows 

 of punctations on the elytra. 1 They live on the ground, 

 and during the daytime they are concealed underneath 

 boards and stones, but at night they fly and climb trees 

 and shrubs in search of other insects. They are most 

 abundant near watercourses, and are sometimes found on 

 the seashore. Some species emit ill-smelling fluids, often 



with a popping sound. These 

 fluids serve to defend them from 

 their enemies. Some species are 

 vegetable feeders, for instance 

 one species whose larva? are 

 destructive in the South to 

 young Indian corn. 



The next two families, Dytis- 

 cidae 2 and Gyrinidae, 3 include 

 beetles which are quite as de- 

 structive to animal life of the 

 water as the runners are to those 

 of the land. The Dytiscidse are 

 often large species, which have long, thread-like antennae. 

 The Gyrinidse have short antennae and whirl around on 

 the surface of the water, often in groups. Each eye is 

 divided into an upper half, used for looking into the air, 

 and a lower half, used for looking into the water. The 

 larvae of both of these families have a long and spindle- 

 shaped or flattened body and live in the water. 



1 Fig. 43. 



2 BiJTrjs, diver ; 5vriK6s, fitted for diving. 



3 From 7u/o6s, circle ; because this beetle swims in a circle. 



FIG. 43. Calosoma scrutator, the 

 searcher, a ground-beetle. Nat. 

 size. Photo, by W. H. C. P. 



