1922] 



Kershaw and Miiir: Genitalia of Homoptera 



205 



within gl, the apex of p within g2 and the apices of gs within g3, 

 but the last is obscure and the more difficult to trace. This 

 shows their true homologies and also shows the homologies of 

 the male and female, which can be represented as follows : 



Nymph 



Adult cf 



Adult 9 



Anterior gonapophyses 

 Median gonapophyses 

 Posterior gonapophyses 



gl 

 g2 

 g3 



Genital plates 

 Aedeagus 

 Genital styles 



Outer fProcesses of 

 Inner \ ovipositor 

 Ovipositor Sheaths 



In many species of Cercopidse gl in the adult male are joined 

 together into a single plate. 



COMPOSITION OF THE ^DEAGUS. 



The aedeagus is a complex structure and the homologies of 

 its parts not clear. In the adult Philaeniis leucophthalmus 

 (Linn) there is a large, chitinous bulb (Fig. 8, pa) which may 

 represent the periandrium, and a straight penis (Fig. 8, p). 

 On the ventral aspect of the apex of the penis is the orifice or 

 gonopore (Fig. 8, gpr). It is possible that during copulation 

 the ejaculatory sac may be protruded or evaginated and the 

 gonopore or functional orifice be situated upon it. Figure 8 

 shows this sac slightly protruded. At the apex of the penis 

 there are two large, curved hooks, the penis hooks (Fig. 8, ph), 

 and below them four smaller processes in a circle. In the later 

 nymphal stages the area around the base of g2 is invaginated, 

 carrying with it both g2 and the bases of g3, (Fig. 10). The 

 penis hooks (ph) of the adult lie within the bifurcations of g2, 

 (Fig. 11). The bulb or periandrium (pa) evidently arises 

 from the body wall, round the base of g2. The fact that g2 

 first arises as a single lobe and the bifurcation arises later 

 may indicate that it is only the penis hooks that are homologous 

 to the paired processes of the female and the rest of the gedeagus 

 (the penis and bulb) are formed by outgrowths of the body wall. 



