Fig. 404.— Hirudo medicinalis. A, dorsal ; B, ventral aspect ; a. anus ; a. s anterior sucker ; 

 e. 1. first, and e. 5. fifth pair of eyes; g. p. S- male gonopore ; g. p. 9. female gonopore ; 

 mth. mouth; np. 1. first, and np. 17. seventeenth pair of nephridioporcs ; p. s. posterior 

 sucker ; s.p. segmental papillae ; I. — XXVI. segments. 



