ANATOMY. 599 



The parts I refer to are, firstly, the ligula; secondly, 

 the lingua (or lingula) ; and, thirdly, the epipharynx. 

 The first and second mentioned parts are very likely 

 to be confused from the similarity of names, combined 

 with considerable resemblance in position and form ; 

 and possibly that danger is increased in this book by 

 PI. I, fig. 4, where the lingua (g) is intended to be 

 seen through the labium and maxillae from the (arti- 

 ficially produced) transparency of the latter organs ; 

 but, in consequence of the lingua having been printed 

 as a strong instead of a faint line, this effect is not 

 produced. It is well, therefore, to make the matter 

 as distinct as possible, and with that view I have given 

 on PL LIII, tigs. 5 to 8, some drawings or diagrams 

 of the arrangement of the parts in question in C'epheus 

 latus, a very good species for the purpose, which at 

 the time of the publication of vol. i was far too rare 

 to be used for dissecting purposes ; but I have found 

 many more specimens of it since. These drawings 

 and the descriptions here given will I hope render it 

 easier to recognise the parts. 



The Ligula is simply a chitinous piece forming a 

 prolongation forward of the labium itself, and springing 

 from the distal edge of the latter; or, if " labium " be 

 taken as a general name for the whole, then from the 

 distal edge of the mentum it is usually more or less 

 triangular ; in Insects it may be anchylosed to the 

 mentum and divided from that part only by a sutural 

 line, or may be attached by a ginglymous articulation ; 

 it may also be a single azygous piece or divided longi- 

 tudinally into two paired pieces, which when large are 

 usually called " paraglossse." In the OrtbatidcB the 

 ligula, when present at all, which is not usually the 

 case, is, as far as I know, always anchylosed to the 

 mentum, and only divided by a sutural line, and it is 

 usually a paired organ, apparently serving partly to 

 close the mouth-opening and to protect the Imgua. 



The Lingua (or Lingula) is described at p. 120 ; it 

 is a delicate membranous organ arising from the inner 



