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(a) Male genital segments. 



The terminal segment in the male is in the form of a chitinous 

 cyh'nder. whose profile often affords good specific characters; 

 this is the pygophor. On looking at this from behind, it is 

 seen to be divided into two parts, a smaller dorsal cavit}-. the 

 anal tube ; and a larger ventral one, the genital tube. 



The anal tube contains the mobile anal style,* while the geni- 

 tal tube contains the following: 



(i) the mobile genital styles which are articulated near the 

 ventral margin, being situated more or less horizontally on look- 

 ing into the tube. 



(2) the oedeagus, which is situated about the middle of the 

 pvgophor and is more or less vertical on looking into the tube, so 

 that the ])ygophor must be tilted to observe the former properly. 

 It is perforated by the muscular, protrusible, penis; 



(3) the lateral margins of the pygophor are often thickened 

 and dilated and also interiorly produced into hooks or spines. 

 There are also hooks or spines close to. o^r proceeding from, the 

 wall between the anal tube and the genital tube, and also on the 

 posterior margin of the pygophor. 



The following is a i)artial synonymy of the parts: 



1 Pvgophor^Pygofer Ed\\'ar(\s=. I ffcrtrargcr lMelK'r=f '///- 

 rar app:udi.v Signovet= II yp.>pygiiim Kolenati. 



2 Anal Tuhe=AiiUvior part of the segment Sharp=^-lftcrrohr 

 Melichar.. 



3 Anal Sty\Q=Rectal cauda Sh3iTp=Afterstieleheii Fiebcr. 

 This is the termination of the alimentary canal. 



4. Diaphragm = 77/r transverse deflected ivaU separating the 

 ana! tnbe from the genital tnhe (Sharp). 



5 Oedeagus=:Por^r penis ¥\ehQ\-z^P enistrager Melichar. This 

 is the "part of the male organs through which pass the mem- 

 branous structures connected with the ejaculatory duct." 



6 Genital Siy\es-=LateraJ accessory pieces Sharp=.S'/y// and 

 Griffel Fieberr^Ctrc/ of some authors. 



7 A'entral Margin of VygorAior ^=zPosterior edge of segment=: 

 Lip Sharp. 



The various hooks are not specially named. 



* This has sometimes been omitted in the drawings. 



