1919] 



Cort: Excretory System of a Stylet Cercaria 



277 



That the excretory system of Cercaria polyadena has reached its 

 full development in arrangement and number of flame cells is sug- 

 gested by the fact that the capillary groups have been definitely 

 established, and by the finding in the literature of the descriptions 



Fig. 1. The excretory system of Cercaria polyadena. Ventral view; body 

 spines, stylet and eystogenous glands are not shown ; acct, accessory collecting 

 tube; act, anterior collecting tube; o, bladder; c, capillary; cot, common collecting 

 tube ; exp, excretory pore ; /, flame cell ; os, oral sucker ; pet, posterior collecting 

 tube; ph, pharynx; st, stylet; vs, ventral sucker. 



