FIG. in. HirudO medicinalis. A, dorsal; B, ventral aspect. a. anus ; a. s. 

 anterior sucker ; e. /, first, and e. J, fifth pair of eyes ; gf>. $ , male gonopore ; 

 gp. 9 female gonopore ; mth, mouth ; np. /, first pair of nephridiopores ; 

 np. 17, seventeenth pair ;/. s. posterior sucker ; s. p. sensory papillae ; I XXVI, 

 segments. (Partly after Whitman.) 



