2 THE SPONGES OF THE WEST-CENTRAL PACIFIC 



each of these four, intensive study was made at widely scattered points. The 

 four groups are the Marianas, the Palaus, the (eastern) Carolines, and the 

 Marshalls. They are sometimes collectively termed Micronesia. 



Only shallow water sponges are treated here. A few of the specimens 

 from Bikini and Eniwetok were dredged, but not from very deep water, 

 about 50 meters at the deepest. Others were collected by hand, while wading. 



My usual method of collection was as follows : First, the services of one 

 or more native so-called divers would be obtained to gather specimens. These 

 men are able to swim (rather than dive) down to depths of many meters and 

 to continue collecting at such depths for more than a minute. Then we 

 would set out in some small craft, by necessity one with a low freeboard. 

 During the summer, at one time or another, we employed dugout canoes, out- 

 rigger sailing canoes, rowboats, inflated life rafts, occidental-type sail boats, 

 outboard-powered boats, and inboard motor boats. When the divers were 

 in the water, I was able to point out desired specimens, using a viewing box 

 or water-glass. I made extremely frequent use of this device, which was 

 capably built for me by the carpenters of the University of Hawaii, and 

 viewed many square miles of sea-bottom. It was easy to see clearly to 

 depths of 5 meters, often reasonably clearly to depths of 10 or more meters. 

 In water less than 2 meters deep, I was able to do some of the collecting 

 personally. Such was the richness of the fauna, and the industry of the 

 divers in some places, that it was a hectic task to keep up with the needed 

 bottling of specimens and the taking of notes. 



The present discussion is divided into two parts. The first is a descrip- 

 tion of the Porifera which were studied. The second describes the regions, 

 and the ecological relationships of the sponges thereof. 



The collections which are discussed here aggregate some 183 species. It 

 should be noted that, as in all animal groups (but especially in the Porifera), 

 species may be difficult to delimit. That is to say, how much difference may 

 be tolerated as variation within a single species? For the commoner sorts, 

 I believe that the field study method has given an excellent basis for conclu- 

 sion. For the uncommon forms, such conclusions must still be only tentative. 



More than a hundred species are treated as new. This is quite to be 

 expected in view of the previously unstudied nature of the territory and the 

 tendency of evolution to provide unique species in insular locations. Yet 

 there is a problem here, because many students of sponges in the nineteenth 

 century named species with utterly inadequate descriptions and no illustrations 

 or poor ones. An example is found in Kieschnick's descriptions of East 

 Indian species. Many of his descriptions are less than thirty words in total 

 length ; some less than twenty words. They are completely devoid of 

 measurements and provide no illustrations at all. If there are any types, 

 their location is unknown. Because of the wars, it may well be that no 

 specimens remain. Some names, thus unrecognizably given, may have been 



