mth 



~ - feri_ 



3 -p< 



VI 



VII 



VIII 



IX 



XIV 



XV 



B 



.... - -W xxin p^z 



7~ xxiv " 



FIG 411 Hirudo medicinalis. .4, dorsal ; 7J, ventral aspect ; a. anus; o. s. anterior sucker; 

 'e. J. first, and P. 5. fifth pair of eyes; </. p. 6 . male gpnopore ; g. p. 9- fenuili- <>nopore; 

 mth. mouth; np. 1. first, and np. 17. seventeenth pair of nephridiopores ; /*. x. posterior 

 sucker ; .v. /. sc^inunlal papilko ; I. XX\'l. segments. 



