72 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[518 



EXPLANATION OF PLATE 



Figures 

 Fig. 5- 



I to 4. Free hand drawings of stages in the process of encystment of 



Cercaria urbanensis. X about 70. 

 Mature Cercaria urbanensis, ventral view. Cystogenous glands not shown. 

 X 140. 



Posterior locomotor projection of Cercaria ephemera. From Ssinitzin. 

 Posterior locomotor projection of Cercaria imbricata. From Looss. 

 Posterior locomotor projection of Cercaria urbanensis. X 433. 

 Cross section of the tail of Cercaria urbanensis. X 433. 

 Immature redia of Cercaria urbanensis... X 88. 

 Mature redia of Cercaria urbanensis. X 88. 



Mature redia of Cercaria urbanensis, showing constrictions. X 44. 

 Cross section of immature redia of Cercaria urbanensis. X 433. 



