B 



Ttfi.tT 



Fig. 117. — Hirudo medicinalis. A, dorsal; B, ventral aspect, a, anus: a. s, 

 anterior sucker; e. t. first pair of eyes; e. 5, fifth pair; gp. $ , male gonopore; 

 gp. Q , female gonopore; mt/t, mouth; np. 1, first pair of nephridiopores; 

 up. /y, seventeenth pair; p. s, posterior sucker; s.p, sensory papillae; I-XXVI, 

 segments. (Partly after Whitman.) 



204 



