(>45 



Fig-. SI. HeueJ of same, enlaiKvl. AfU-r tUn.li. 1TS2. Taf. Ill, 



fig. i. 

 Fig. 82. Anterior portion of head, showing the arrangement 



of the hooks upon the rostellum. x240. After Kiabl>?, 



1869, Tab. VIII, flg. 154. 

 Fig. 83. Isolated hooit. x920. After Krabbe, 1869, fig. 155. 

 Fig. 84. Strobila, natural size. After von Linstow, 1872A, 



Taf. XXI, .fig. 3. Host: Goosander. 

 Fig. 85. Head. x90. After von Linstow, 1872A, Taf. XXI, fig. 5. 

 Fig. 86. Isolated hook. x500. After von Linstow, 1872A, Taf. 



XXI, fiff. 2. 

 Fg. 87. End of proglottid with extruded ciiTus. xl50. After 



von Linstow, 1872A Taf. XXI, fig. 4. 

 Fig. 88. Head of Taenia gracilis tadornae from the common 



sheldrake (Tadorna tadorna). After Lonnberg, 1889, 



PI. I, fig. 1. 

 Fig. 89. Free cysticercoid in the perch (Pei'ca fluviatilis). x350. 



After von Linstow, 1872A, PI. XXI, fig. 1. 

 Fig. 90. ExcretOTj' system of the head and neck After Mrazek, 



1891, Tab. V, fig. 16. Zeiss 3, D. 

 Fig. 91. End cell of excretory system. After Mrazek, 1891, Tal>. 



V, fig. 17. Zeiss 3, F. 



Plato VIII, Figs. 92-99.— D'ltpanidotaenia gracilis. 



Fig. 92. A cysticercoid in process of development. A differen- 

 tiation is noticed into the body and the tail, and a 

 small knob is noticed on the anterior extremity. The 

 6 oncospheric hooks are present in the tail. After 

 Mrazek, 1891, Tab. VI, fig. 25. 



Fig. 93. Another stage of the cysticercoid. An invagination is 

 noticed on the anterior extremity; the middle portion 

 of the body is occupied by a cavity filled with a 

 spongy tissue. After Mrazek, 1891, Tab. VI, fig. 26. 



Fig. 94. Cysticercoid with the anterior portion of the tail: h., 

 peripheral hyaline layer; e., excretory canals; pr., 

 vibratory cells (see PI. VII, fig), "Pronephriostomes." 

 Zeiss 3, D. After Mrazek, 1891, Tab. V. fig. 13. 



Fig. 95. Normal form of hook. Zeiss 3, F. After Mrazek, 1891, 

 Tab. V, fig. 14. 



Figs. 96-98. Three hooks, with variously arranged chitiii. Zeiss 

 3, D. After Mrazek, 1891, Tab. V, fig. 15a-c. 



Fig. 99. A cysticercoid with extended head: r., rostellum; c, 

 cyst: pr., tail with oncospheric hooks. Zeiss 1, D. 

 After Mrazek, 1891, Tab. VI, fig. 18. 



