16 AN INTRODUCTION TO ENTOMOLOGY. 



Sometimes, however, the paraglossae are large, exceeding t1 

 From the base of the ligula arise a pair of appendage the labial ///// 

 labial palpus consists of from one to four freely movable segments. 

 In the form of the labium ju>t described, the correspondence of it 



.e is not easily seen ; but this is much more evident in 



the labium of some of the lower insects, as for example a cockroach (Fig. 3)- 

 Here the organ is very deeply cleft; only the submentum 

 and mentum remain united on the median line ; while the 

 ligula consists of t net maxilla-like parts. It is 



easy in this case to trace the correspondence referred 

 to above. Each lateral half of the submentum corre- 

 sponds to the cardo of a maxilla ; each half of the menium, 

 6 stipes; while the remaining parts of a maxilla are 

 represented by each half of the ligula, as foil 

 the base of the ligula there is a part (< ') which hears the 

 labial palpus; this appears in the figure like a basal sc_ 

 of the palpus ; but in many insects it is easily seen that it 

 is undoubtedly one of the primary parts of the organ ; it has been named the 

 Jkttpigsr, and is the homologue of the palpifer of a muxillu. The trunk of each 

 half of the ligula is formed by a large sclerite (c*) to which I believe attention 

 has not been called heretofore. This evidently corresponds to the subg. 



lie distal extremity of this subgalea of the labium there are two append- 

 ages. The lateral one of these (<:') is the para^losstt, and obviously c 

 sponds to the galea. The mesal one (V 1 ) corresponds to the lacinia or inner 

 lobe. This part is probably wanting in those insects in which the glossa con- 

 sists of an undivided part ; and in this case the glossa probably represent 

 united and more or less elongated subgaleae. 



Tlif Epipkdrynx and the Hypopharynx. In addition to thr mouth-parts 

 described above, either the labrum or the labium may bear on its ental sin 

 within the cavity of the mouth, a more or less tongue-like organ. If born 

 the labrum, it is termed the epipharynx (9) ; if by the lahium, the hypupharvn.v 

 1 'in- epipharynx and the hypopharynx an '>th 



developed in the same insect, except in some Hymenoptera. The form and 

 ! the hypopharynx are analogous to those of the tongue of higher 

 animals. On this account it has been named the lingua or tongue. 1 ' 

 both of these terms have been applied to the glossa, it is best to designate this 

 part as the hypopharynx, and to avoid the use of the terms lingua and toi 

 as liable to be ambiguous. 



The Thorax. 



The tho ic second or intermediate region of the body. It 



y distin; .vhich arc three pah 



(1 one or two pairs of wings. This region consists <>f tl; 

 segments. The cephalic or nt is named the 



e second, the incsotliorax (15); and the third, the 

 (16). Each segment bears a pair of K -^ : and in win the 



by the second and third segments. 



