84 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[530 



EXPLANATION OF PLATE 



Fig. 63. 



Fig. 64 

 Fig. 65 

 Fig. 66 

 Fig. 67 

 Fig. 68 



Cercaria douthitti, ventral view. X 195. 



Cross section of Cercaria douthitti thru eye-spots. X 433. 



Diagram of the excretory system of Cercaria douthitti in the region where 



the tail joins the body. X about 400. 

 Cross section of Cercaria douthitti thru the acetabulum. X 433. 

 59 to 62. Cross sections of Cercaria douthitti showing the passage of the 



ducts of the cephalic glands thru the oral sucker. X 433. 

 Section thru a sporocyst of Cercaria douthitti while still included in the 



snail's liver. X 433. 

 A portion of a sporocyst of Cercaria douthitti. X. 44. 

 A portion of a sporocyst of Cercaria isocotylea. X 44. 

 Sporocyst of Cercaria isocotylea. X 44. 



Stylet of Cercaria isocotylea from ventral and side view. X 433. 

 Cercaria isocotylea, ventral view. X 311. 



