• 33 
Excretory system. — At the caudal end, slightly dorsad, is an in- 
vagination, surrounded by a row of cells, and apparently represent- 
ing the excretory vesicle. Excretory canals are also visible on 
section. 
Systematic position. — From the foregoing account it will be seen 
that this worm is an agamic distome with genital pore about midway 
between the acetabulum and the caudal margin (compare for in- 
stance Clinostomum) . 
