180 THE UNIVERSITY SCIENCE BULLETIN. 



PLATE IV. 



Fig. 26. Cercaria fusiformis, dorsal view. X 72. 



Fig. 27. C. fusiformis, ventral sucker closed. X 160. 



Fig. 28. C. fusiformis, ventral sucker open. X 160. 



Fig. 29. C. fusiformis, ventral sucker lateral view. X 160. 



Fig. 30. Cercaria magnacauda. X 72. 



Fig. 31, Body of C. magnacauda. X 260. 



Fig. 32. Cercaria quieta. X 72. 



Fig. 33. Ventral sucker of C. quieta. X 260. 



Fig. 34. Mouth of redia of C. magnacauda, longitudinal section. X 260. 



Fig. 35. Mouth of redia of C. magnacauda, cross section. X 260. 



Fig. 36. Redia of C. fusiformis. X 30. 



Fig. 37. Redia of C. quieta. X 36. 



Fig. 38. Redia of C. magnacauda. X 104. 



PLATE V. 



Fig. 39. Cercaria echinocauda. X 72. 



Fig. 40. Cercaria echinocauda. X 72. 



Fig. 41. Redia of C. echinocauda. X 36. 



Fig. 42. Longitudinal section through C. echinocauda. X 160. 



Fig. 43. Cross section through C. echinocauda. X 160. 



Fig. 44. Tail of C. echinocauda, longitudinal section. X 160. 



Fig. 45. Tail of C. echinocauda, cross section. X 160. 



Fig. 46. Cercaria inversa. X 72. 



Fig. 47. Redia of C. inversa. X 72. 



Fig. 48. Cross section of tail of C. inversa. X 144. 



Fig. 49. Cross section through cephalic glands, C. inversa. X 144. 



Fig. 50. Cross section through oral sucker, C. inversa. X 520. 



Fig. 51. Longitudinal section through excretory pore, C inz^erso. X 260. 



PLATE VI. 



Fig. 52. Cercaria haskelli, dorsal view. X 144. 



Fig. 53. C. haskelli, longitudinal section. X 160. 



Fig. 54. C. haskelli, cross section through tail. X 160. 



Fig. 55. Sporocysts of C. haskelli. X 72. 



Fig. 56. Cercaria kansiensis. X 260. 



Fig. 57. Lateral view of stylet, C. kansiensis withdrawn. X 260. 



Fig. 58. Lateral view of stylet extended, C. kansiensis. X 260. 



Fig. 59. Sporocyst of C. kansiensis. X 72. 



Fig. 60. Cercaria gregaria. X 144. 



Fig. 61. Longitudinal section of snail liver infected with C. kansiensis. 

 X44. 



Fig. 62. Sporocyst C. kansiensis, cross section. X 260. 



PLATE VII. 



Reconstructions of the cercarise described in the preceding pages all drawn 

 to scale X 36. The numbers refer to the indices accompanying plates I- VI. 



Numbers 8' to 56' refer to sporocysts and redlse corresponding to the cercariae. 



