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LEPIDOPTERA 



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

 a copulatory apparatus ; its dorsal portion bears a process called the 

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

 and below 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," the 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, which 

 se come together when 

 closed, and may be 

 covered externally with 

 scales like the rest of 

 the abdomen. Peytou- 

 reau considers that the 

 uncus is really the dorsal 

 plate of a tenth segment, 

 and that the scaphium 

 is the tenth ventral 

 plate. Thus, according 

 to this view, the ninth 

 segment is extensive and 

 complex, being very 

 highly modified in all 

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

 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 tibiae sometimes bear 

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

 front tibia usually possesses on its inner aspect a peculiar 

 mobile 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, 



Fig. 160. — Acherontia atropos. The termination of S 

 body, one side removed. IX, Ninth dorsal plate ; 

 IX', ninth ventral ; s, lobe, saccus, of ninth 

 ventral plate ; X, tenth dorsal plate, or uncus ; 

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

 anus ; b, chitinised band of scaphium ; I', valve or 

 clasper ; c, hooks, or harpes, of clasper ; p, penis 

 (or oedeagus). (After Peytoureau.) 



