800 Mii. J. inTciiii; O.N iivj)i!iiiD,s [May 24, 



sxsterisks in the following list, have thus been added to the 

 fauna of the Indian Ofean. As to the wider relationships: — 

 Three s])efies are peculiar to the Indian Ocean {Corydendrium 

 sessile, IleheUa crateroides, Cnh/cella oliyista), leaving twenty- 

 six to be accounted for. Of these, twelve are so widely 

 distriliuted that their occurrence, emphasizing the normal nature 

 of the fauna, cjin give no indication of special affinity: three 

 being found in the Atlantic and North Pacific Oceans and in Aus- 

 tralasian sens (Opercidarella lacerta, Plumidaria setacea, AnteneUa 

 secimdaria) ; two in the Atlantic and North Pacific Oceans 

 [Fei'lyonhnusi-epens, Camjicm nlaria raridentata) ; and seven in the 

 Atlantic Ocean and in Malay-Australian seas {Peimcwia disticha, 

 Ualeckim tenellitm, Campamdaria corrugata, Ilehella calcarata, 

 Sertidarella polyzonias, Idia prisiis, Dlphasia dnjitalis). Of the 

 remaining fouiteen, four have been found only in the Atlantic 

 Ocean {Eadendriitvi attennaUim, Cuspidella costata, Lafoea serrata, 

 Lafoca veil usta), seven in the Mahiy- Australian nven^Euxlendrmm 

 yeneralis, Cladocoryne haddoni, Ifaleckim simjdex, Thyroscyphv^ 

 vitiensis, Sertidarella cylindrica, Sertidarella quadridens, Sertidaria 

 tnrlnnata), one in the North Pacific Ocenn ( 77/ yroscyphus re;/ alar is), 

 and two in both the last-named aieas {Lytocarjnis 2Jennarius and 

 L. phieniceus). 



The closer relationshij) is obviously with the fauna of the 

 Pacific Ocean (re})resented Ijy ten distinctive species), and in 

 jiarticular with the Malay-Australian portion of that ocean 

 (repi-esented l)y seven species). The significance of the apparent 

 Atlnntic affinity is minimised when it is understood that of 

 the fom* species common to it and the Mei'gui Archipelago, one 

 [Eudendriuni attenuatum) is identified with much doubt, Avhile 

 the remaining three are very minute epizoic species, the presence 

 of which in other regions may conceivably have been overlooked. 

 It is remarkable thiit of the thirty species recorded, seven- 

 teen were found c]ind)ing upon Luger llydi-oids and one upon 

 a Polyzoon, the majm-ity being minute, habitual epizoa, be- 

 longing in the main to the faiiiilics Hnlecida\ Campanulnrida>, 

 Campanulinida', and L;ifocida'. The examiniition of this collection, 

 and of others, leaves with me the distinct impression that the 

 epizoic llydroids are not distrilnited indiscriminately upon all 

 types of Hydroid host. Thus, in general, the membei's of the 

 family Plumulariche remain comparatively free from extraneous 

 growths — a fact to be correlated, perliai)s, with their possession 

 of nemato]>hores ; while colonies, belonging especially to the 

 family Sertidnrida*, are occasionally so overgrown that the 

 structures of the host are much obscured. Even distinct pre- 

 ferences for certain species may be obst'r\ed. Taking, for ejvch 

 epizoic sjiecies in this collection, the total ninubers of stations at 

 which it was found, and adding those numbers for all the epizoic 

 species, we find that epizoic species were found at a sum total of 

 forty Jive stations. At thirty-tiro of these Jdia prislis was either 

 theonlv host, or nne ot tjir hosts where more than one species 



