80 ILLINOIS BIOLOGICAL MONOGRAPHS [526 



EXPLANATION OF PLATE 



Fig. 37. Mature redia of Cercaria trivolvis. X 88. 

 Fit'. 38. Immature redia of Cercaria trivolvis. X 88. 

 Fig. 39. Mature Cercaria trivolvis, ventral view. Cvstogenous glands not shown. 



XI95. 

 Fig. 40. Cercaria rubra freed from cyst, ventral view. X 195. 

 Fig. 41. Cercaria rubra inside of cyst. X 195. 

 Fig. 42. Anterior end of Cercaria rubra, dorsal view. X 195. 

 Fig. 43. Cercaria reflexae, ventral view. Cystogenous glands not shown. X 88. 



