372 EXTERNAL ANATOMY OF INSECTS. 



upper separation from that of the manitrunk. It 

 affords a point of attachment to several muscles of 

 the wings, &c. a 



C Dorsolum (the Dorslet). The piece which lies be- 

 tween the Collare and Scutellum, to which the pro- 

 praghm is anteriorly attached, and which bears the 

 upper or anterior organs of flight b . It includes 

 the Pteropega, Elytra, Tegmina, Hemelytra, Ales 

 Super iores, and Tegulcc. 



a Pteropega (the Wing-socket). The space in which 

 the organs for flight are planted. That for the se- 

 condary or under-wings is in the Metathorax . 



b Elytra (the Elytra). The upper organs for flight, 

 when they are without nervures, and uniformly of 

 a thicker harder substance than membrane whether 

 corneous, or coriaceous ; lined by a fine membrane ; 

 and when closed, united by the longitudinal suture d . 

 They include the Axis, Sutura, Epipleura, Alula, 

 and Hypoderma, and are peculiar to the Coleoptera 

 and Dermaptera. 



A Axis (the Axis). A small, prominent, irregular pro- 

 cess of the base of the Elytrum, upon which it turns, 

 and by the intervention of which it is affixed to the 

 Dorsolum, in the anterior wing-socket e . 



B Sutura (the Suture). The conflux of the sutural or 

 inner margins of the two Elytra, where when closed 

 they unite longitudinally f . 



» Plate XXII. Fig. 8, 11. A'. 



" Ibid. Fig. 8. Plate VIII. Fig. 3, 12, 14, 16. IX. Fig. 1, 7, 8, 

 10—12, 15, 19, 21. i. 

 c Plate VIII. Fig. 14, 20. IX. Fig. 11, 12. and XXII. Fig. 8. b" . 

 d Plate X. Fig. 1.; and XXVIII. Fig. 1—8, 10. 

 e Plate XXVIII. Fig. 3—5. b'". f Plate X. Fig. 1. d" . 



