210 ANATOMY. 



The male organs of the Lepidoptera (for example, of Deilephila 

 Euphorbia, PI. XXVI. f. 14 17-) display two exterior horny valves 

 densely covered with scales ; these valves are attached to a projecting 

 horny ridge upon the circumference of the sexual organs (f. 14 a, a). 

 Beneath these exterior valves there are two interior finer, pergamenta- 

 ceous, and delicately haired ones, which, as well as the exterior ones, 

 correspond together at their internal margin, and on their external 

 margin they stand free. Each runs upwards in a sharp fine hook, and 

 has beneath also, contiguously to it, a membranous process, which par- 

 tially covers the penis (fig. 15. displays this inner valve from the 

 inside). The penis lies between these inner valves ; it is a pergamen- 

 taceous somewhat bent tube, which is open and emarginate in front 

 (f. 15 and 17-)- Upon the upper side, opposite the valves, there is a 

 strong, bent, conical hook, which has anteriorly two points, an exterior 

 one which bends inwards, and an interior one which bends outwards, 

 and between the points a conical membranous process projects, which 

 is also perforated (f. 14. c), and forms the anal tube. Both organs, 

 the former internal valves supplied with a hook, and these hooks stand- 

 ing opposed to it, serve, without doubt, to retain the female organs 

 during copulation. 



The male sexual organs of the Diptera have, in the majority of 

 cases, been noticed and figured by Meigen in his monograph of this 

 order * ; we can therefore give a more comprehensive description of 

 them than of the preceding ones. 



We everywhere find exterior, and even often interior valves, and 

 between these the penis. The chief difference of this order is, that the 

 male sexual organs in most instances project beyond the apex of the 

 abdomen, and lie there exposed, which was not observed in the former 

 ones. We thence find the prepuce, or rather that membranous bag 

 which contains the withdrawn organs to be wanting in the Diptera. 

 The differences of the exterior valves is very great. In the family of the 

 Tiptilaria I formerly described a new insect (Nematocera nubectilosa), 

 which was distinguished by large projecting sexual organs t. Two 

 thick, large, black, shining processes, each of which bears a small 

 bright brown reflected appendage, form the exterior valves, and be- 



* J. W. Mcigen's Systematische Beschreibung tier bekannten Europaischen, zueifliig- 

 ligen Insekten, 6. B. mit Kupfem, 1818 32. 



-f- Comp. Thon's Archiv. dei Entouiolngie, vol. ii. p. 36. PI. I. f. 13. 



