THE SPONGES OF THE WEST-CENTRAL PACIFIC 285 



regard it as a serious loss that it did not prove to be feasible for me to 

 investigate the outer reefs at Truk or the Palaus. I doubt that many sponges 

 would be found on them. Dredging just outside the reef might, however, yield 

 quite a few species, as indicated by my studies in Ebon Atoll of the Marshalls. 



In eastern Ponape, Matalanim Province, there is an island called Nan 

 Matal on which occur immense and interesting ancient ruins which are built 

 of basalt blocks. Between Nan Matal and the main island, the water is so 

 shallow that one may easily wade back and forth. These shallows have a 

 bottom of sandy mud and a fairly dense stand of a monocotyledonous sea- 

 weed sometimes called turtle grass, which has leaves about 1 cm wide and 30 

 to 60 cm long. These shallows have a distinctive and abundant sponge popula- 

 tion, especially of Spongia zimocca, subspecies irregularis, and Anthosigmella 

 vagabunda. Other fairly common sponges in this locality included Neopetrosia 

 pandora, Adocia turquoisia, Biemna fortis, and Nailondria maza. These 

 sponges often surround leaves of the seaweed, doubtlessly employing them as 

 a substrate, as well as the fragments of dead coral which occur among the 

 sand and mud. 



Eniwetok Atoll is usually regarded as a part of the Marshall Islands, 

 but it is so far to the west of the others that one might almost classify it with 

 the eastern Carolines. I did not visit it myself, but collections were sent to me. 



J. P. E. Morrison collected there in 1946, chiefly during April. He dredg- 

 ed out in the open lagoon. I did no dredging and studied only the portions 

 of the lagoon which were 10 meters deep or less. His dredgings include the 

 first six of the following seven species : 



1 Thorectopsamma mela. I found this abundant throughout the Mar- 

 shalls and present, but not quite so common, at Ponape, Truk, and the 

 Palaus. It is not reported elsewhere. The only previous records of a 

 species of Thorectopsamma have been Australian and Bermudan. 



2 Callyspongia fistular.is. I found this also in the Marshalls (Majuro and 

 Ebon) ; previous records have been from the Indian Ocean. 



3 Agelas mauritiana. I also found this at Majuro and Ebon. Morrison 

 found it also at Bikini. It is the only sponge found in 1946 at both 

 Eniwetok and Bikini. 



4 Lissodendoryx calypta. This is a unique record. 



5 Clathria abietina. I found this also at Truk. Previous records were 

 probably, but not certainly, East Indian. 



6 Anthosigmella vagabunda. I found this abundant throughout the 

 Marshalls, Ponape, Truk, and the Palaus. Earlier records are from 

 the Indian Ocean and Philippines. 



7 Hezekia walkeri. This was not dredged. I found it common at Likiep 

 in the Marshalls and also at Ponape and the Palaus. Bayer found it at 

 Bikini in 1947. It is one of the four species found both at Bikini and 

 Eniwetok in that year. 



