The Male Genital Armature of the Dermaptera. 419 



apex of the proparameres, is directed backwards in repose, so that 

 the ejaculatory duct is doubled back upon itself; but in erection 

 the preputial sacs are directed forward, so that the ejaculatory 

 ducts are straightened. But in the Eudermaptera there is no dis- 

 cernible trace of the lost penis, and the remaining preputial sac 

 is not reversed, but directed in repose as in erection, the protrusion 

 being the only difference in the latter condition, consequently the 

 ejaculatory duct is never bent; the preputial sac here seems to 

 take its origin from the basal part of the weakened proparameres. 



When we remember this, it is surprising to find that in 

 Hemimerus and Arixenia,, which are looked upon as primitive 

 forms, one penis is rudimentary. In the former we have what is 

 really a Eudermapterous form of penis, with single direct praeputial 

 sac and ejaculatory duct. 



In Arixenia the rudiments of the abortive preputial sac and 

 ejaculatory duct are discernible, and the functional sac is direct, 

 as in the Eudermaptera, and not reversed in repose, as in the 

 Protodermaptera. We find a somewhat, but not quite similar 

 arrangement in the Karschielliiuv, as shown by Zaeher, but the 

 degeneration of the second penis is less accentuated than in 

 Arixenia, the rudimentary preputial sac being discernible. 



It is surprising to find in these apparently primitive groups 

 features in the reproductive organs, and also in the opisthomeres 

 which are associated in the so-called higher section of the earwigs. 

 Either the Arixenia and Hemimerina are less primitive than 

 usually considered, or we must modify the opinion which I have 

 expressed, that the progressive degeneration of the opisthomeres is 

 a good measure of the higher development in the Dermaptera. 



The fact that in such primitive groups as the Arixenina, and 

 Hemimerina, and in the Karschiellinm, one of the lowest of the 

 Protodermaptera, the genitalia approach the form which generally 

 characterises the Ev.dermaptera, or higher earwigs, compels us to 

 believe that the reduction of one penis is not necessarily evidence 

 of a higher stage of development, and to my mind robs the male 

 reproductive system of much of the value that has been attached 

 to it as evidence of the phylogenetic relationship of the various 

 sub-divisions of the Dermaptera. 



I am now prepared to modify the arrangement proposed in the 

 Genera Insectorum (1911). I propose to sink the Paradermaptera, 

 reducing them to family rank, within the Protodermaptera. The 

 strongly flattened body is not enough to warraut the separation of 

 the Paradermaptera, since, if it were, we should be obliged to raise 

 the rank of the Platylabiina} and of the Sparattinse ; neither has 

 the squamopygidium, since an apparently identical structure is 

 admittedly only given generic value in the case of Gonolabina. 



The other chief alteration is the transference of the Allostethinse 

 from the Labiduridm to the Pj/gidicranidie, on the strength of the 



