GENERAL INTRODUCTION. 27 



armature, Lobes, processes and teeth appear very often in 

 connection with the reduction of the clasper. 



The clasper consists of an external and an internal plate. 

 The inner sheath is more or less covered with hairs, and is in 

 most species raised into special armatures. There is very 

 often a conspicuous subdorsal longitudinal setiferous fold. 

 The ventral armature of the clasper is termed the harpe. 



The external plate of the clasper is divided by a longitudinal 

 rib-like incrassation into a narrow dorsal and a large ventral 

 portion. The dorsal part is generally concave above the rib. 

 Upon and near the rib there is found in a great number of 

 Sphingid^ a peculiar modification of the scaling (fig. 7 H). 

 This is thought to be an organ of friction, by means of which 

 a sound of some kind is produced. There are two types of 

 this organ, the one confined to the Sppiingid^: Asemanophorje 

 the other to the Sphingid^ Semanophor^. In the former 

 group it is a patch of scales lying more or less flat upon the 

 clasper, and in the latter group it consists of lanceolate scales 

 which are half erect. 



The area between the two claspers and the tenth sternite 

 is more or less membranaceous. There is a central hole, 

 of which the edges are more or less raised and chitinized, 

 forming the penis -funnel (P-F). 



The penis-sheath projects from and is supported by the penis- 

 funnel. It is provided at the end or near it with processes 

 and teeth of various shapes and sizes. Within the sheath is 

 found the membranaceous penis proper, the duct of the 

 sperma. This duct can be pushed out, and has, in most 

 cases, an armature of its own. 



$. In order to examine the female organs it is necessary 

 to remove the seventh to tenth segments and relax them, 

 and then draw them apart, which can be done with the help 

 of a pin. The vaginal armature, lying hidden in a cavity in 

 most species, must be pushed outwards by pressure from the 

 inside to become plainly visible. 



A. Diagram of copulatory apparatus of male. ix. t, ninth segment 



(tegumen) ; x. t, tenth segment (uncus) ; A, anus ; CI, clasper ; 

 H, harpe ; P, penis-sheath ; P-F, penis-funnel ; pi, pleural attach- 

 ment. 



B. 2 genitalia of Protoparce rustica ; end of abdomen, segments 6 to 10, 



ventral aspect, vu, vm, ix, x, abdominal segments. 



C. As fig. B, segments 8 to 10, lateral aspect. 



D. Sixth and seventh abdominal segments of Cephonodes hylas, ventral 



aspect. 



E. Sixth and seventh abdominal segments of Sesia fadus, ventral 



aspect. 



F. Eighth tergite of Meganoton nyctiphanes. 



G. Palpus of Cechenena lineosa, internal aspect, a, sensory hairs; 



sgm. 1, 2, segments 1 and 2. 

 H. Friction -patch of clasper of Psilogramma menephron. 



