STATES OF INSECTS. 127 



that your own visage would present an appearance not very 

 engaging while concealed by such a mask; but it would 

 strike still more awe into the spectators, were they to see 

 you first open the two upper jaw- like plates, which would 

 project from each temple like the blinders of* a horse; 

 and next, having by means of the joint at your chin let 

 down the whole apparatus and uncovered your face, em- 

 ploy them in seizing any food that presented itself, and 

 conveying it to your mouth. Yet this procedure is that 

 adopted by the larvse provided with this strange organ. 

 While it is at rest, it applies close to and covers the face. 

 When the insects would make use of it, they unfold it 

 like an arm, catch the prey at which they aim by means 

 of the mandibuliform plates, and then partly refold it so 

 as to hold the prey to the mouth in a convenient position 

 for the operation of the two pairs of jaws with which they 

 are provided. Reaumur once found one of them thus 

 holding and devouring alarge tadpole; — a sufficient proof 

 that Swammerdam was greatly deceived in imagining 

 earth to be the food of animals so tremendously armed 

 and fitted for carnivorous purposes. Such an under-lip 

 as I have described is found in the tribe of dragon-flies 

 {JLibellulind) ; varied, however, considerably in its figure 

 in the different genera. In the larva of Libellula Fab., 

 such as Libelhda depressa, &c. it is of the shape above 

 described ; so exactly resembling a mask, that if Ento- 

 mologists ever went to masquerades, they could not more 

 effectually relieve the insipidity of such amusements and 

 attract the attention of the demoiselles, than by appearing 

 at the supper table with a mask of this construction, and 

 serving themselves by its assistance. It would be difficult, 

 to be sure, by mechanism to supply the place of the mus- 



