506 HARRY M. MILLER, JR., AND FLORA E. NORTHUP. 



PLATE I. 



All drawings were made with the aid of a camera lucida, except where otherwise 

 stated. 



FIG. i. Cercaria setiferoides; general view. X 150. 



FIG. 2. Free-hand diagram of excretory system pattern in redia of C. setijer- 

 oides. X 40. 



FIG. 3. Immature redia of C. setiferoides, showing pharynx and gut. X 92. 



FIG. 4. C. dipterocerca; immature redia. X 88. 



FIG. 5. General view of C. dipterocerca. X 56. 



FIG. 6. Nearly mature redia of C. setiferoides, containing germ balls and almost 

 fully formed cercariae. X 72. 



FIG. 7. C. dipterocerca; dorsal view of body showing eye spots, digestive and 

 gland systems, and locations of most easily observable flame cells. Reproductive 

 system cell mass between ventral sucker and excretory vesicle. X 415. 



FIG. 8. Nearly mature redia of C. dipterocerca. X 138. 



FIG. 9. Outline of body of C. quissetensis, when in extreme extension. X 42. 



FIG. 10. C. setiferoides; dorsal view of body showing eye spots, digestive and 

 gland systems, and cell masses representing future reproductive system. Only 

 excretory vesicle and entrance of main lateral collecting vessels are shown. X 34 2 - 



