88 



THE VOYAGE OE H.M.S. CHALLENGER. 



Spongelia horrida, 

 Psammoelema ramosum, 

 Psamnioclema vosmaeri, 

 Psammoelema foliaceum, 

 Psammcrpemma densum, 

 Psainmopemma porosum, 



Spongidae. 



Cosdnnderma confragosum, 

 Cosdnoderma dentlndaium, 

 Gosdnoderma altum, 

 Euspongia officinalis, var. lohosa, 

 HipiMspongia anomala, . 

 Hippospongia mauritiana, 

 Cacospongia levis, 

 Cacospongia amorpha, 

 Cacospongia murrayi, 

 Cacospongia vesicidifera, 

 Cacospongia procAimbens, 

 Cacospongia dendroides, 

 Cacospongia spinifera, . 

 Cacospongia tubercidata, 

 Cacospongia intermedia, . 

 Cacospongia irregularis, 

 Cacospongia oligoceras, . 

 Cacospongia compaeta, . 

 Cacospongia collectrix, . 

 Stelospongos longispimts, 

 Carteriospongia radiata, 

 Carteriospongia otahitica, 



Aplysinidae. 



lAiffaria variabilis, 

 Verongia hirsuta (?), 

 Verongia tenuissima {1), . 



PAGE 



42 

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 48 



50 

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69 

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Bathtmetrical Table, . 



73 



IV. Concluding Ekmarks, ...... 



Short Eecapitulation of the Deductions of the Foregoing Chapters, 

 Affinities of the Keratosa and their place in the General System, 

 Definition of the ideas " Genus" and " Subgenus," 

 Scheme of a Conjei-turally Natural Arrangement of the Keratosa, 



75-85 



75 

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 83 



Problems to be Solved La Order to Bender an Undoubtedly Natural Arrangement of them realisable, 83 



