2 Transactions of the Society. 



Protodermaptera. As Zacher truly remarks, in the lower group 

 the crreater diversity of form in the genital organs but represents 

 Nature's attempts at the best type, which we find m the more 

 highly developed section in the reduction of the proparameres, the 

 disappearance of one penis with its concomitant appendages itie 

 uniformity of the structure of the body and of the genita ha are 

 clearly correlated, as Zacher observes, and consequently the 

 reproductive organs are less useful to the systematist than m the 

 Protodermaptera. . , , 



Zacher opened the discussion on this group m a paper entitled 

 " Das mannliche Copulationsorgan und das~ System der Euder- 

 maptera " * He agrees with my half-formed wish to connect the 

 GMisodddie with the LaUidm. He suggests that the Sparattmi^ 

 and Spongipliorinie, both mainly Neotropical groups, form the link 

 between the two, and quotes my own opinion that Auckenomus 

 represents the passage between the SparattimB and the Uieiiso- 

 chinx. Earlier authors placed Avxhenovius in the latter group, i 

 do so in the former. It is premature to express a final opinion, since 

 the genitalia of but a few species have been examined, but it is 

 noticeable that both in the Labiid^v and in the Chehsochidrnji 

 posteriorly widened pronotum is very common. Possibly this 

 character has more significance than we are yet aware ot, but 

 thougli of apparently no very great importance, it is an undoubted 

 fact that both in the Labiid<v and in the ChelisocUdx. this shaped 

 pronotum is very common. As a character we may compare it 

 with the keels on the femora of most of the Pygidicranidx, which 

 is a more valuable character than would appear at first sight. 

 Probably there is a phylogenetic origin to each, and convergence 



is not the cause. , -r. i ^ 



I quite agree to Zacher's proposal to divide the Eudermaptera 

 into two main groups, the LaUida} and Chelisochidie on the one 

 hand, and the Forjiculinm and remaining subfamilies on the other. 

 The Eudermaptera, or higher Earwigs, are sharply distinguished 

 from the lower group, or Protodermaptera, by the possession ot a 

 sincrle penis: there is but one preputial sac, or penis proper, 

 with a single virga and ejaculatory duct. The proparaineres are 

 also reduced, being but feebly chitinized, so that it is difiicult to 

 say which is the true base of the segment, and the hmge is tar 

 less well-marked than in the lower group, though always better 

 chitinized than tlie rest of the structure. In erection, the prseputiai 

 sac is protruded between the metaparameres, which, as a rule 

 do not seem to alter their position, but in my preparation ot 

 Opisthocosmia (?) pcecilocera Borg. and Mesochelidura bohvari i)ubr. 

 they are opened outwards, moving more or less freely about the 

 hinc^e, though less freely than in the Protodermaptera. ■ 



* Zeitchr. wiss. Insektenbiol. , viii. (1912) p. 276. 



