86 ILLINOIS BIOLOGICAL MONOGRAPHS [532 



EXPLANATION OF PLATE 



Fig. 69. Stylet of Cercaria polyadena, ventral view. X 433. 



Fig. 70. Cercaria polyadena, ventral view. Cystogenous glands not shown. X311. 



Fig. 71. Cercaria polyadena in cyst. X 140. 



Fig. 72. Sporocyst of Cercaria brevicaeca. X 88. 



Fig. 73. Stylet of Cercaria brevicaeca, ventral view. X 433. 



Fig. 74. Free hand drawing of Cercaria brevicaeca, ventral view. Cystogenous 



glands not shown. X about 150. 



Fig. 75. Stylet of Cercaria hemilophura, side view. X 433. 



Fig. 76. Cercaria hemilophura, ventral view. Cystogenous glands not shown. 



X 140. 



Fig. 77. A portion of a sporocyst of Cercaria hemilophura. X 44. 



Fig. 78. Cercaria hemilophura, side view. X. 140. 



Fig. 79. Stylet of Cercaria leptacantha, ventral view. X 433. 



Fig. 80. Immature Cercaria leptacantha, ventral view. X 433. 



Fig. 81. Sporocyst of Cercaria leptacantha. X 88. 



