EXTERNAL ANATOMY OF INSECTS. Sit 
vex scales, which in many Orders, particularly Hy- 
menoptera, cover and defend the base of the Upper- 
Wings *. 
D. Scurettum (the Scutellum). A piece, usually tri- 
angular, which follows the Dorsolum ; and in Co- 
leoptera is often only a continuation of it—placed 
between the base of the Elytra or upper-wings °. 
EK. Franum (the Frenum). A piece that lies under the 
lateral margin of the Scutellum and Dorsolum, or is 
adjacent to it; and which in many cases connects 
with the base of the upper organs of flight, so as to 
prevent their dislocation, by being pushed too far 
outwards °. 
F. Pnysteca (the Pnystega). A corneous scale or plate, 
which covers certain pneumatic vessels, usually 
supported by the Scapularia, in Libellulina, &c. be- 
coming dorsal 4. 
2. Meprrecrus (the Mid-breast). The underside of the 
frst segment of the alitrunk*. It includes the 
Peristethium, Scapularia, Mesosternum, Med:furca, 
and Pedes Intermedui. 
A. PeristetHium (the Peristethium). The anterior 
piece of the Medzpectus, which intervenes between 
the Brachia and mid-legs *. 
B. Scaputaria (the Scapulars). ‘Two pieces, one on 
each side the Medipectus, which succeed the Peri- 
stethium, and lie between the mid-legs and the Pte- 
@ Pirate IX. Fic. 5,1). g’. > Prares VIII. IX. XXVIIE. #’. 
Sabi: fe 4 Ppate IX, Fie. 7. m’. 
* Prate VIII. Fic, 4, 13, 17. and IX. Fic. 3, 8, 12. d. 
f Ibid, n’. 
