296 THE VOYAGE OF H.M.S. CHALLENGER. 



Family IV. X E N 1 1 D ^. 



Xenia, Savigny. 



The few species known of this genus would seem to be very widely scattered, occurring 

 at the Fijis, Amboina, and in the Red Sea. 



Family V. r G a N i D .s:. 



Organidiis, Danielssen. 



The only species described, Organidus nordenshioldi, Danielssen, was taken off the 

 north-western coast of Sj^itzbergen. 



Family VI. T u B i p o R I D ^. 



Tuhipora, Linneus. 



In the Indian Ocean the species are found in the Red Sea, and extending south of 

 the Equator to the Seychelles ; in the Pacific Ocean they have been found at most of 

 the island groups. New Ireland, the Fijis, the Philippines, &c. 



Family VII. CoenulariidvE. 



Cornularia, Lamarck. 



Comularia cornucopias, Schweigger, perhaps the only known species, is recorded 

 from the Mediterranean. 



Rhizoxenia, Ehrenberg. 



Species of this genus have been found on the coast of Norway (Sars), at Naples, and 

 the Moluccas. 



Clavularia, Quoy and Gaimard. 



The now somewhat numerous species of this genus have been described as follows : — 

 from the coasts of Norway, Clavidaria horealis, K. and D., Clavularia arctica, 

 K. and D., Clavularia stormi, K. and D., Clavularia frigida, Dan.; from the 

 Mediterranean, Clavularia crassa (Mar. and Kow.), and Clavularia petricola. Mar. 



