556 THE STUDY OF INSECTS. 



The Horned Passalus, Passalus cornutus (Pas'sa-lus cor- 

 nu'tus). differs greatly in appearance from our other stag- 

 beetles (Fig. 674). It is a large shining, black beetle, with 

 a short horn, bent forwards, on the top of the head. This 

 beetle and its larva are found in decaying wood. The larva 

 is remarkable for possessing only four well-developed legs. 



Family SCARAB^EID^E (Scar-a-bae'i-dae). 



The Scarabceids (Scar-a-bce' ids) or the Lamellicorn (La-mel'li- 

 corn) Beetles. 



This is a very large family, including beetles that repre- 

 sent a wide range of variation in size, form, and habits. 

 They are mostly short, stout-bodied beetles, of which the 

 well-known June-bugs or May-beetles represent the most 

 familiar type. The most useful character for distinguishing 

 these insects is the lamellate form of the club of the antennae, 

 the segments constituting it being greatly flattened, and 

 capable of being brought close together. It is this character 

 that suggests the name lamellicorn beetles. 



According to their habits, the members of this family can 

 be separated into two well-marked groups the scavengers 

 and the leaf-chafers. 



THE LAMELLICORN SCAVENGERS. 



The lamellicorn scavengers in both the larval and adult 

 states feed upon decaying animal and vegetable matter. 

 Nearly all the species live in the dung of" animals, chiefly that 

 of horses and cows. But the members of one genus, Trox, 

 feed upon decaying animal matter, and. a few species feed 

 upon fungi. The following are the most common represen- 

 tatives of this division : 



I. The Trimble-bugs. These are the most familiar of all 

 dung-beetles, for their peculiar habits have attracted much at- 

 tention from the earliest times. They are of rounded form, 

 and the wing-covers are shortened so as to expose the tip 



