4Z4h MODERN CLASSIFICATION OF INSECTS. 
separate motion, and are supported by a single piece at the back (fig. 
114. 10.0, x and x being the two lateral files, one partially pushed 
forwards ; 114. 11. represents these three pieces in another position, 
showing more clearly that ¥ is but the produced edge of x). This 
instrument has been carefully described by Réaumur (tom. v. pl. 18.), 
who represents in his various figures the alternate protrusion of the 
lateral files, as well as the central groove down the back of the sup- 
porting dorsal piece. On inspecting this last piece, it appears proba- 
ble that it consists of two pieces firmly soldered together. I do not, 
however, believe that these two pieces have the slightest motion inde- 
pendent of each other, or open at the tip, as represented by Burmeister, 
Handb. Transl. pl. 24. f. 3, 4. This author has further described and 
figured the two lateral files as united together, and forming a ‘“ su- 
perior distended sheath, with teeth on the margin *,” and the dorsal 
supporting piece as “ the lower sete,” evidently considering this 
part as consisting of two sete, enclosed in the distended sheath; and 
as the point of this supporting piece is represented as bifid and pro- 
truded considerably beyond the extremity of the serrated lateral organ, © 
it is evident that Burmeister considers the middle piece as the piercing 
part, and the serrated part as the supporting sheath: so also M. Doyere, 
in the Crochard edition of the Régne Animal (pl. 95. fig. 2.1 and 
2. k), considers the serrated lateral pieces as performing, in the act of 
perforation, “les fonctions de grappins,” and the central piece as 
“instrument réellement perforant ;’ but the peculiar structure of 
these lateral files, so admirably fitted for making incisions in vegetable 
fibre, and the curious form of the middle dorsal piece (fig: 114. 12.0.) 
grooved along the sides,— the groove being internally dilated, and receiv- 
ing the dilated edge of the serrated piece, and thus retaining it in its 
place, (as represented in my jig. 114. 12. being a transverse section of 
these instruments +,) —are, I think, sufficient proofs that the serrated 
lateral pieces are the real organs of perforation, and that the dorsal 
piece is but an organ of support. Ihave dissected so many specimens 
* Burmeister has certainly erred in regarding these two lateral serrated pieces as 
forming one organ; see his pl. 24. fig. $. aa, 5. and 7. aa; whilst M. Doyére’s 
two figures, 2. 1 and 2. k, give an incorrect idea, by omitting one of the lateral pieces 
in each figure. 
1 The figures of the transverse sections of these organs given by Burmeister and 
Doyere, are incorrect, the middle supporting piece being placed downwards instead 
of being represented as the dorsal part. 
