314 



LEPIDOPTERA 



less extent to the inside of the body, and modified to form part ot 

 a copulatory apparatus ; its dorsal portion l:)ears a process called the 

 " uncus " ; the anal orifice opens on the inner face of this process, 

 and Lelow it there is another process — -developed to a greater or 

 less extent- — called the " scaphium." The ventral portion of the 

 ninth segment bears a lobe, the " saccus " (Peytoureau, I.e.). On 

 each side of the ninth abdominal segment there is a process called 

 the " valve," tlie internal wall of which bears some hook-like or 

 other processes called " harpes " ; it is continued as a membrane 

 surrounding the " oedeagus," or penis, and — bearing more or 

 less distinct prominences — connects with the scaphium. In many 

 forms the parts alluded to, other than the valves, are concealed 



by the latter, w^hich 

 come together when 

 closed, and may be 

 covered externally with 

 scales like the rest of 

 the abdomen. Peytou- 

 reau considers that the 

 imcus is really the dorsal 

 plate of a tenth segment, 

 and that the scaphium 



Fig. 160. — Acherontia atro2}os. The termination of 6 jg the tenth ventral 



body, one side removed. IX, Ninth dorsal plate ; ■■ ^^, -, . 



IX\ ninth ventral ; s, lobe, saccus, of ninth plate. i llUS, according 



ventral plate ; X, tenth dorsal plate, or uncus ; |^q this vieW the ninth 



sc, scaphium, or tenth ventral plate ; «, position of . ' . , 



anus ; b, chitinised band of scaphium ; T', valve or segment IS extensive and 



elasper : c, hooks, or harpes, of clasper ; 2>: penis Qoiin3lex bein*'' Very 



(or oedeagus). (After Peytoureau.) i ' ' ■■ 'T • vi 



highly modified m all 

 its parts : while the tenth segment is greatly reduced. Tlie 

 structure of the male organs is simpler in Lepidoptera, and less 

 varied than it is in the other great Orders of Insects. There 

 are seven pairs of abdominal spiracles on the upper parts of the 

 membranous pleurae. 



Legs. — The legs are long, slender, covered with scales, and 

 chiefly remarkable from the fact that the tiliiae sometimes liear 

 articulated spurs on their middle as well as at the tip. The 

 front til)ia usually possesses on its inner aspect a peculiar 

 moljile pad ; this seems to be in some cases a combing organ \ 

 it also often acts as a cover to peculiar scales. The tarsi 

 are five-jointed, with two small claws and a small apparatus, 



