XVI LIST OF ILLUSTRATIONS 



FIG. FAG 



94. Vertical section of i4wr^/ia — after Claus . . . j86 



95. Diagram of life -history of ^wr^/io — after Haeckel . . 188 



96. Lucernaria — after Korotneff . . . . .189 



97. Diagram of Lucernaria — after Allman . . .189 



98. External appearance of Tealia crassicornis . . . 191 



99. Vertical section of a sea-anemone — after Andres . .192 

 100. Section through sea-anemone (across arrow in Figure 99) — 



after Andres. ...... 193 



loi. Z, Diagrammatic section of Zoantharian ; ^, of Alcyonarian 



— after Chun . . . . . . 194 



102. The formation of a coral shell (Astroides) — after Pfurtscheller 196 



103. Structure of Antipatharians ..... 197 



104. Diagrams of Types of Alcyonaria — after Hickson . .198 



105. Corallium rubrum, a corner of a colony — after Lacaze- 



Duthiers . . . . . • • 199 



106. Alcyonarian spicules ...... 200 



107. Diagram of a gymnoblastic Hydroid — after Allman . . 202 



108. Graptolites ....... 202 



109. Hydroids — after Hincks ..... 203 

 no. Campanularian Hydroid — after Allman . . . 204 



111. Diagram of a Ctenophore — after Chun . . . 206 



112. Hydroctena. Amedusoid with hints of Ctenophore structure 207 



113. Commensalism of sea-anemones and hermit-crab . . 208 



114. Portions of excretory system of flat-worms . . . 211 



115. Diagram of Turbellarian — after Lang . . . .213 



116. Structure of liver fluke — after Sommer. From ventral sur- 



face. The branched gut (g.) and the lateral nerve {l.n.) 

 are shown to the left, the branches of the excretory 

 vessel (e.v.) to the right ..... 



117. Reproductive organs of liver fluke — after Sommer . 



118. Life-history of liver fluke — after Thomas 



119. Diagram of life-cycle of liver fluke .... 



120. Male and female Bilharzia — Schistosomum hcsmatobium — 



after Looss ....... 



121. Front end of the head of TcBnia solium .... 



122. Diagram of reproductive organs in Cestode joint — con- 



structed from Leuckart ..... 



123. Life-history of T^nm so/mw — after Leuckart 



124. Diagram of life-history of Tania solium 



125. Diagrams of bladder-worms ..... 



126. Diagrammatic longitudinal section of a Nemertine [Amphi- 



porus lactifloreus), dorsal view — after M'Intosh. . 231 



216 

 217 

 219 

 221 



222 

 225 



226 



227 



228 

 230 



