CELLAR BEETLES AND MEAL WORMS 39 



restless, and search about for a suitable place of lodg- 

 ment; having found one to its taste, the grub arches 

 its back and divests itself of its last larval skin, and 

 then passes very rapidly through the resting-stage of 

 pupadom, appearing in an incredibly short time as a 

 perfect insect, ready again to take part in the activities 

 of life. At first it is pale, and the elytra are so trans- 

 parent that the body can be seen through them ; after 

 a few days, however, they acquire their characteristic 

 ferruginous colour and opacity. The pupa shows dis- 

 tinctly all the parts of the perfect insect, the head, 

 wings, and legs being bent down underneath the body. 



These insects do not confine their attentions to farina- 

 ceous substances ; they are also animal feeders, and are 

 amongst the enemies to be dreaded by the keeper of 

 collections of natural objects ; their larvae will excavate 

 the carcase of a dried insect as effectually as will those 

 of Dermestes or Anthrenus. 



Another bakehouse insect is Gnathocerus cornutus, 

 which is identical in colour with TriboUum, and very 

 similar in shape, but somewhat larger. Its names, Ghiath- 

 ocerus, "jaw-horn," and cornutus, "horned," both refer 

 to a peculiarity of the male 

 only, by which that sex can 

 be easily distinguished from 

 all other members of this 

 group. The mandibles, i.e., 

 the biting jaws, are each in 

 the form of a long horn, 

 the pair of which, project- 



iTiw wmei'rlaT>ahlv in ffrmt FIG. 16. Head of Gnathocerus 

 ing considerably in tront cornutus (much magnified). 



of the head, and curling 



upwards, give the insect a most formidable aspect. 



The head (Fig. 16) is altogether an odd-looking object, 



