415 



The two vasa deferentia join a rounded vesicle (vs) which 

 Hes on top of the organ of copulation and from which a single 

 ejaculatory duct (de) runs frontad, entering the penis close to 

 the tip. About one-sixth the way from the vesicle forward the 

 duct throws oft" a small short duct (dr), widening at the apex. 

 This blind branch (text-fig. 25, dr) is evidently the remnant of 

 the second ejaculatory duct present in the primitive Earwigs. 

 The duct, on entering the organ of copulation, is enlarged to a 

 small elliptical vesicle with very thick walls of longitudinal 

 muscles and then forms several loops before joining the more 

 strongly chitinised ejaculatory duct of the copulation-organ. 



While the penis is flat in the Earwigs and Hcmimcrus in a 

 dorso-ventral sense, it is cylindrical in Arixenia, widening at the 

 apex. It is composed of two bundles of transverse muscles, 

 which form the lateral and ventral walls of the cylinder, and a 

 bundle of longitudinal muscles, which forms the dorsal wall. 

 Upon this dorsal bundle there lies a transparent membrane 

 expanded between two wire-like, strongly chitinised rods (le), 

 which run parallel from the proximal end of the penis to near 

 the apex, somewhat diverging distally, and act as a lever or 

 manubrium to the parameres (par). The two parameres of the 

 Earwig-penis consist of a weakly chitinised proximal and a more 

 strongly chitinised distal portion, the latter usually being armed 

 with one or two teeth or hooks. In Arixenia the parameres are 

 very weak. The apical piece is subcylindrical, finger-shaped, 

 feebly chitinised, and studded with blunt sensory setae resembling 

 papilke. The right and left rods of the before-mentioned le\'er 

 (le) join the end-piece of the paramere of their respective sides 

 at its lateral surface, the rod being here flattened and firmly 

 fixed to the paramere. The end-pieces of the parameres being 

 dorso-lateral, the apical cavity of the penis called the pra;putial 

 sack (Verhoeff) lies ventrally to them. The pneputial sack 

 of Arixenia is deeper than the penis is broad, and contains a 

 special armature consisting of four very strongly chitinised and 

 irregularly shaped curved bars (B'-B*) with rounded as well as 

 pointed projections. The armature looks dittercnt according to 

 the side from which it is examined. A distal projection (B*) re- 

 sembles more or less the neck, head, and beak oí a bird, and there 

 is another pointed hook, but re\'ersed, farther proxiinally (B'). 



