344 ERNEST CARROLL FAUST. 



2. Comparison of the system in the cercaria and redia of this 

 species yields evidence that there is a fundamental homology 

 of the units in the hermaphroditic and the parthenogenetic 

 generations of this fluke. 



REFERENCES CITED. 

 Faust, E. C. 



'18 Studies on Illinois Cercariae. Jour. Parasit., 4, 93-110, 2 pi. 



'19 The Excretory System in Digenea. I. Notes on the Excretory System of 



an Amphistome, Cercaria convolnta nov. spec. BIOL. BULL., 36, 315321. 

 'iga The Excretory System in Digenea. II. Observations on the Excretory 

 System in Distome Cercariae. BIOL. BULL., 36, 322-339. 



