COLEOPTERA. 559 



III. The Earth-boring Dung-beetles, — These beetles are 

 of a rounded convex form (Fig. 676). They differ from all 

 other dung-beetles in having the antennae 

 eleven-jointed, and in the labrum and man- 

 dibles being visible from above. This is a 

 small group, less than twenty North American 

 species having been described. The popular 

 name is derived from that of the typical genus, fig. 676. 

 Geotriipes (Ge-o-tru'pes), which signifies earth-boring. Those 

 species the habits of which are known live in excrement. 

 The females bore holes into the earth either beneath the 

 dung or near it ; into these holes they convey a quantity of 

 the dung: this is to serve as food for the larvae, an ^^^ be- 

 ing laid in each hole. This is an approach to the peculiar 

 habits of the tumble-bugs. 



IV. The Skin-beetles. — The members of this group are 

 oblong, convex species, in which the surface of the body 

 and wing-covers is usually very rough, and covered with a 



crust of dirt, which is removed with great dif- 

 ficulty. They are small or of medium size ; 

 our most common species measure from one 

 third to one half inch in length. The abdomen is 

 Fig. 677. covered by the elytra ; the feet are hardly fitted 

 for digging, but the femora of the front legs are greatly di- 

 lated. Our species all belong to the genus Trox (Fig. (>^^^* 

 They feed upon dried, decomposing animal matter ; many 

 species are found about the refuse of tanneries, and upon 

 the hoofs and hair of decaying animals. 



THE LAMELLICORN LEAF-CHAFERS. 



The leaf-chafers are herbivorous insects which in the 

 adult state usually feed upon the leaves of trees, but many 

 of the species devour the pollen and petals of flowers. In 

 the larval state some of these insects are found in rotten 

 wood ; others live in the ground, where they feed upon 

 the roots of grass and other plants. These larvae are thick, 



