o'roke: larval trematodes. 179 



EXPLANATION OF PLATES. 



With the exception of Plate VII, all figures are drawn \\ath the camera 

 lucida. The abbreviations are after the plan adopted by Cort. 



ABBREVIATIONS USED, 



ac-acetabulum. ir-intestine of redia. 



6p-birth pore of redia. ?a-locomotor appendage of redia. 



6r-brain. /c-large central cells of tail, 



c-concretions. m/-musc!e layer, 



cff-cystogenous glands. os-oral sucker, 



ccff-cephalic glands. p-pigmentation. 



dc-ducts of ccg. p6-pharyngeal bulb, 



e-eyespot. pr-pharynx of redia. 



es-esophagus. ra-reproductive anlage. 



ex-excretory system. s-stylet. 



cxp-excretory pore. sr-stylet of redia. 



exd-excretory duct. sc-cercariae in sporocysts. 



exr-excretory vessel. sg-stylet glands, 



gb-germ ball. sir-wall of sporocyst. 



!-intPstinal caecum of cercaria. rs-ventral sucker. 



PLATE I. 



Fig. 1. Cercaria cortii. X 61. 



Fig. 2. Cross section of C. cortii through brain. X 122. 



Fig. 3. Cross section of C. cortii through reproductive anlage. X 122. 



Fig. 4. Cross section of tail of C. cortii. X 244. 



Fig. 5. Longitudinal section of tail of C. cortii. X 244. 



Fig. 6. Cyst of C. cortii, dorsal \'iew. X 61. 



Fig. 7. Cyst of C. cortii, lateral view, x 61. 



PLATE II. 



Fig. 8. Cercaria diastrophora Cort. X 144. 



Fig. 9. Cross section of C. diastrophora through oral cavity. X 288. 



Fig. 10. Cross section of C. diastrophora through pharynx. X 144. 



Fig. 11. Cross section of C. diastrophora through reproductive anlage. 

 X 144. 



Fig. 12. Cross section of tail of C. diastrophora. X 288. 



Fig. 13. Immature redia of C. diastrophora. X 144. 



Fig. 14. Mature redia of C. diastrophora. X 72. 



Fig. 15. Longitudinal section through excretory pore of C. diastrophora. 

 X 576. 



PLATE III. 



Fig. 16. Cercaria inhabilis Cort, dorsal view. X 44. 



Fig. 17. Immature Cercaria inhabilis. X 36. 



Fig. 18. Immature redia of C. inhabilis. X 36. 



Fig. 19. Mature redia of C. inhabilis. X 36. 



Fig. 20. Cross section of C. inhabilis through intestinal caeca. X 160. 



Fig. 21. Cross section of C. inhabilis through excretory pore. X 160. 



Fig. 22. Cross section of tail of C. inhabilis near body. X 160. 



Fig. 23. Cross section of tail of C. inhabilis near posterior end. X 160. 



Fig. 24. Cercaria gracilis. X 160. 



Fig. 25. Redia of Cercaria gracilis. X 36. 



