INSECTS 



CHAP. 



divided mentum, and closes the mouth beneath or behind, 

 according as the position of the head varies. In most Insects 

 the labium appears very different from the maxilla, but in many 

 cases several of the parts corresponding to those of the maxilla 

 can be clearly traced in the labium. 



The mentum is an undivided, frequently very hard, piece, 

 continuous with either the submentum or the gula, and anterior 

 to this are placed the other parts, viz. 

 the labial palpi and their supports, the 

 palpigers ; beyond and between these 

 exists a central piece (Fig. 52, B, e\ 

 about whose name some difference of 

 opinion prevails, but which may be called 

 the ligula (languette of French authors), 

 and on each side of this is a paraglossa. 

 In the Orthoptera the single median 

 piece the ligula of Coleopterists is 

 represented by two divided parts. In 

 some Insects (many Coleoptera) there is 

 interposed between the mentum and the 

 palpigers a piece called the hypoglottis 

 (Fig. 52, B, &). It is not so well ascer- 

 tained as it should be, that the pieces of 

 the lower lip bearing the same names in 

 different Orders are in all cases really 

 homologous, and comparison suggests that 

 FIG. 52. Maxilla and lower the hypoglottis of Coleoptera may pos- 



lip of Coleoptera. A, Max- .,, 



iiiaofPoMoftw.-a, cardo ; sibly represent the piece corresponding 

 b, stipes ; c, paipiger ; d, to the mentum of Orthopterists, the so- 



palpus ; e, inner or infe- 1ln * i i_ 



rior lobe or lacinia ; /, called mentum oi beetles being in that 



outer or superior lobe or cage the su bmentum of Ortliopterfsts. 

 galea : B, Labium of Har- . i 



paius caliginosus: a, men- There is another part of the mouth 

 turn; b hypo'giottis ; c, t w hich we may call special atten- 



palpiger (support of the 



labial palp) ; d, palp ; e, tion, as it has recently attracted more 

 ligula;/, paraglossa. atten tion than it formerly did; it is a 

 membranous lobe in the interior of the mouth, very conspicuous 

 in Orthoptera, and called the tongue, lingua, or hypopharynx ; 

 it reposes, in the interior of the mouth (Fig. 51, 0), on the 

 middle parts of the front of the labium ; it is probably not 

 entirely lost in Coleoptera, but enters into the composition of the 



