xiv GENERAL INDEX. 



CHAPTER VI. 



HYDKOZO A (continued ) ACALEPILE. 



Page Sec. 



ACALEPHJS General description of the 104 . 267 



PULMONIGRADA 105 . 270 



Tissues entering into their composition . . . 106 . 271 



Physiological interest attaching to their organization 106 . 272 



Digestive system of Rhizostoma .' . a -; . . . 106 . 273 



Cassiopea Borbonica 107 . 275 



Cyanea aurita 108 . 277 



Marginal excrementitious orifices . . . 110 . 283 



Movement of fluid in the alimentary tubes 1 10 . 284 



Muscular structure observable in some species . Ill . 285 



Circulation of globules enclosed in vascular canals Ill . 286 



Nervous system of the Medusae . . . Ill . 287 



Oculiform specks 112 . 288 



Auditory vesicles 112 . 289 



Reproduction by gemination 113. 292 



Alternate generations in the Medusiform Acalephae 113 . 294 



Biseruality of the Acalephas 114 . 295 



Female generative organs of Cyanea aurita 114. 296 



Ovigerous pouches 114 . 297 



Structure of ova in the ovaria 115 . 298 



Three forms of ova contained in the ovigerous pouches . . . . 115 . 299 

 The ciliated embryos on leaving the ovigerous pouches assume the 



form of Hydra 115 . 300 



Reproduction of the hydriform embryos by stolons, gemma, and 



bulblets 115 . 301 



Segmentation of the Hydra tuba into Medusiform young . . . . 115 . 302 



Development of the young Medusa 116. 304 



Arrangement of the alimentary and generative apparatus in Cu- 



vieria carisochroma and Mguorea violacea 117 . 306 



Generative apparatus of Mquorea 118. 307 



CILIOGRADA 119 . 308 



Structure of the locomotive organs in the Beroeform Acalephse . 119 . 309 



Organization of the cilia 119 . 310 



Diffused condition of the vital principle 120 . 312 



Alimentary system of Beroe 120 . 313 



Vascular apparatus ...-, . -. . . . . . 120 . 314 



Circulation 121 . 315 



Anal tubes 121 . 316 



Emunctories of Beroe Forskahlii 121 . 316 



Oculiform speck 121 . 318 



Oculiform organ and nervous system of Lesueuria . . . . . . 122 . 319 



Arrangement of generative system 122 . 321 



Anatomy of Cestum Veneris 123 . 323 



Secretions of the Acalephse 124 . 324 



Their power of stinging 125 . 325 



Phosphorescent light 125 . 325 



PHYSOGRADA 125 . 326 



PhysaUa 125 . 326 



ClRRIGRADA 126 . 327 



Porpita . 126 . 328 



Sail of Velella and Rataria 127 . 328 



DIPHTEA 127 . 329 



Their structure and general history ...". .'/;.;....... . 127 . 330 



