506 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1956 



nesia, Subergorgia mollis and Rumphella antipathes, are common 

 East Indian species that occur also, as expected, in the Palaus. An- 

 other species of /Subergorgia, two magnificent melithaeas, the so-called 

 "Plexaura" ftava, a species of Euplexaura, and Junceella fragilis are 

 more or less common in Palau, indicative of close ties with the East 

 Indies and Philippine faunas. Among the Alcyonacea, Dendro- 

 nephthya occurs in abundance and Studeriotes was found in slightly 

 deeper water in the lagoon, both genera being well represented in the 

 Philippines. These various octocorallian genera are centered mainly 

 in the East Indies-Philippines area, but range also northward to 

 Japan and southward to Australia, thence eastward to Fiji, Tahiti, 

 and Tonga, but reduced in species peripherally. Furthermore, the 

 alcyonarian genera typical of Micronesian reefs, such as Sinularia, 

 Sarcophyton, Lobophytum, and Sphaerella, are represented in Palau 

 by a greater number of species than is usual in the central Pacific 

 atolls. 



The molluscan fauna is notably richer in many elements than that 

 of the Micronesian atolls to the east, especially in such genera as 

 Murex, Spondylus, and Pecten. Since the distribution of Simnia and 

 related gastropods is tied to that of the gorgonians on which they live, 

 they accordingly do not extend very far to the east, probably not be- 

 yond Palau. However, the large egg-cowry (Ovula ovum), 

 which lives on soft-corals, enjoys the much wider range of its hosts. 



The fauna of the Palaus will probably not be found to approach 

 the richness of that of the Philippines, East Indies, and New Guinea, 

 but it certainly far overshadows that of the oceanic atolls. 



PROSPECT 



As we write these words, Project Coral Fish II is continuing the 

 program of investigations embarked upon in 1955. It is anticipated 

 that the field phase of a survey of the fresh-water fish fauna of Babel- 

 thuap, begun in 1955, will be completed successfully during the pres- 

 ent season, and the marine survey continues with special attention to 

 areas not previously visited. The research program has been broad- 

 ened by the addition of an oceanographer to the field party, so that 

 more detailed data regarding the aquatic environment may be 

 gathered. 



During Coral Fish III in 1957, we hope to complete our ecological 

 resurvey of Iwayama Bay, and to make more detailed studies of some 

 of the commensal, symbiotic, and parasitic relationships mentioned in 

 the foregoing pages. The results of the 1956 expedition should permit 

 much more efficient observations on the physical environment and en- 

 hance the value of the Iwayama resurvey. We hope that it will also 



