446 GENERAL INDEX. 



in the planoblasts of Stauridmm produclum and Sijncoryne eximia, 370 ; his discovery of CIavatella> 

 385 ; his discovery of the gonosome of Lar sabellarum, 425. 



Histology of the Hydroida, 110. 



Honiolognes of the Ctt'lenterata, 192. 



Homologous parts in the Hydroida, scheme of, 43. 



Huxley, Prof, his group of the Nematophora equivalent with that of the Cuilenterata of Leuckart, 15; 

 his division of the Coelenterata into Hydrozoa and Actinozoa, 16, 187 ; his monograph of the 

 Siphonophora ; his systematic arrangement of the Hydrozoa, 17 ; his determination of the two con- 

 stituent membranes of the hydroid body, 22 ; his employment of the term ' zooid ;' his definition of 

 the Biological Individual, 22, 7tote, and 107. 



Hydra and its power of budding discovered by Leeuwenhoek, 4 ; investigated by Trembley, 4 ; development 

 of ovum in, 94; spermatogenous tubercles in; ovigerous tubercles in, 93 ; its wide geographical 

 distribution, 160; Hydra compared with Actinia, 194; compared with Lucernaria, 197. 



Hydra viridis, its green corpuscles, 123. 



Hydranths, 24 ; the two largest as yet known belong to species one of which is tropical and the other 

 arctic, 394. 



Hydrallmaitia falcata, its great batliymetrical range, 165. 



Hydractinia cretacea, fossil of the Upper Greensand, 173. 



Hydractitiia Michelini, fossil, of the Miocene, 173. 



Hydractinia pliocena, fossil of the Coralline Crag, 173. 



Hydractinia echinata, liable to be infested by a parasitical pichnogunidan, 202 ; bifurcation of zooids in, 

 204; its anatomy, 220; structure of its hydrophyton, 220; its hydranths and spiral z(joids, 221 ; 

 its gonosome, 222; history of its discovery, 341. 



Hydrocaulus, 27. 



Hydrorhiza, 27. 



Hydroid zoology, retrospect of the leading steps in its progress, 20. 



Hydroid medusa compared with the discophorous medusa, 197 ; compared with the Ctenophora, 197. 



Hydroid, generalised conception of a, 21. 



Hydrophyton, 26. 



Hydrosoma, 22. 



Hydrotheca, 26 ; development of, 72. 



Hydrozoa and Actinozoa, classes of the Coelenterata, 187. 



Hypostome, 24. 



Individuality, biological, 22, note, and 107. 



Johnston, his 'History of British Zoophytes;' he proposes the name Hydroida, 13; his restoration of 



Gmelin's genus Clava, 243. 

 Jussieu, Bernard de, he demonstrates the animality of Tubularia, 5. 



Keferstein and Ehler, their account of buds occurring in the stomach-cavity of ^Egineta geinmifera, 84. 

 Kdlliker, his union of the gymnophthalmic medusoD and the hydroid trophosomes into a single group, 15 

 Kotzebue, his circumnavigatory voyages, 10. 



Kowalewsky, his views as to the common cavity of the Cadenterata, 193, note. 



Krohn, his account of the development of the egg in Cladoneraa, 96 ; his discovery of spermatozoa in 

 certain marine hydroids, 148. 



Lacustrine fauna, the deep, 170. 



Lamarck, his institution of new genera of hydroids, 9. 

 Laminarian zone, its hydroid fauna and associated vegetation, 168. 



Laniouroux, his institution of new hydroid genera; the claims of his nomenclature to acceptance, 9. 

 Laomcdca Jlexuosa, development of ovum in, 85. 



Lar sal/cUarum, its trophosome described by Gosse ; discovery of its gonosome by Hincks, 425. 

 Leeuwenhoek, Ant. von, he discovers Hydra, notices its budding, and sends an account of it to the 

 Royal Society, 4. 



