442 GENERAL INDEX. 



Bathymetrical distribution of the Hydroida, 162; its relation to marine vegetation, 164. 



Bathymetrical zones of Forbes, necessity of their modification, 163; bathymetrical zones of the present 

 monograph, 166; variations in the physical condition of the various parts of the same bathyme- 

 trical zone, 164; great extent of the bathymetrical range of hydroid life, 164. 



Beneden, van. Prof., his memoirs on the canipanularian and tubularian hydroids, 14; his institution 

 of the genus Hydractinia, 14; his litoral fauna of the coast of Belgium, 19; his rectification 

 of Ehrenberg's genus Eudendrium, .331 ; his observations on the medusa of Cladoiwma 

 radiatum, 3-59. 



Bifurcation of zooids in Hydractinia, 204. 



Bimcria vcstita, great extent of its chitinous excretion, 298. 



Blainville, M. de, his ' Manuel d'Actinologie,' 12. 



Blastocheme, 29; how distinguished from gonocheme, 35; various forms of its generative bud, 36. 



Blastostyle, 29 ; its form, 33; true and false blastostyles, 34; its buds, 47; compound blastostyle, 47 ; 

 development of blastostyle, 73. 



Boreo-Celtic province, 162. 



Bougainvillia-medusa traced by Wright and Agassiz to a Eudendrium-like trophosome, 311. 



BougaimiUia Britannica of Forbes probably the adult planoblast of the JEudendrtum ramosum of van 

 Beneden, 313. 



Bougaiuvilia, species provisionally referred to this genus, 318. 



Brandt, his account of the medusoe observed by Mertens, 12. 



Buds formed by medusa;, 82. 



Busk, his observation of transverse strife in the fibrillated tissue of the umbrella, 114 ; his ob- 

 servations on the structure of the lithocyst, 141, note; his observations on the lithocyst under 

 polarized light, 143, note ; on the phosphorescence of medusic, 145 ; his determination of Australian 

 hydroids, 156. 



Calyptoblastea, a sub-order of hydroids ; characters of this sub-order, 189. 



Campanularia, supposed nervous cord in, 138. 



Canalliculation of endoderm in Tubularia, 124 ; in Conjmorpha nutans, 125 ; in Antetmularia 



antennina, 125. 

 Carmarina hastata, Haeckel's account of its metamorphosis, 81. 

 Carpenter, Dr. W. B., his views of the zoological individual, 22, note ; gives the true interpretation of 



the law of alternation of generations, 101. 

 Carus, J. v., his treatise on the Coelenterata, 18. 

 Cartilage-tissue described by Haeckel in the Geryonidse, 115. 

 Cavolini, his researches on the Hydroida of Naples; he describes the production of a medusiform 



gonophore ; he maintains the vegetality of the Nullipores, 8 ; he was the first to observe somatic 



currents in the Hydroida, 130, note: notices the difference between the male and female gonophores 



in Eudendrium racemosum, 341. 

 Ceratostera of Leuckart, 16. 



Chamisso, his discovery of alternation of generations, 10. 

 Chitine, perisarc of the Hydroida composed of, 26. 

 Chlorophylle, green matter of Hydra viridis compared with, 135. 

 Cilia, vibratile, their presence on the walls of the somatic cavity, 123 ; their action in causing the 



somatic currents, 132. 

 Circulation in the Hydroida, 130. 



Cladocoryne, the only hydroid known with the tentacles of its hydranth branched, 379. 

 Cladoncma radiatum, development of eggs in, 96; its anatomy, 216; structure of its gonophore, 217; 



Dujardin's observations on, 357. 

 Claparede, his views of the development of Tubularia, 93, note ; his account of the direct development 



of Lizzia from the egg, 100. 

 Clark, Prof. J., his views of the development of Tubularia, 92, note. 

 Classification of the Hydroida, 187 ; tabular view of hydroid classification, 191. 



