THE SPONGES OF THE WEST-CENTRAL PACIFIC 33 



U.S.N.M. No. 22994, My No. M. 372, collected July 7, 1949, by diver at 



Ebon Atoll, west corner of the lagoon north of the Pearl Pool. The 



depth was 3 meters, and the substrate was dead coral. 

 U.S.N.M. No. 22996, My No. M. 374, collected July 7, 1949, by diver at Ebon 



Atoll, from the open ocean just west of Rube point. The depth was 3 



meters, and the substrate dead coral. 

 U.S.N.M. No. 22864, My No. M. 158, collected July 11, 1949, by diver, at 



Likiep Atoll, southeast corner of the lagoon, near the church. The 



depth was 3 meters, substrate dead coral. 

 U.S.N.M. No. 23089, My No. M. 471, collected August 13, 1949, by diver, at 



Truk, in the west portion of the lagoon, in Lemotol Bay. The depth 



was 4 meters, substrate dead coral. 

 U.S.N.M. No. 23128, My No. M. 511, collected September 6, 1949, by using 



a fish spear, in Iwayama Bay near Ulebsechel Island, Palau Archipelago. 



The depth was 1.5 meters, and substrate was dead coral. 



The species also was collected at Bikini Atoll in 1948 by T. E. Bullock 

 (his numbers C. 335 and C. 102). 



This species was collected also at Eniwetok Atoll in 1948 by T. E. Bul- 

 lock (his number Z 105). 



This species was moderately common at Ailing-lap-lap and was widely 

 distributed. It was similarly common and widespread at Majuro Atoll and 

 Ebon Atoll. It was conspicuously abundant at Likiep Atoll in all regions 

 studied (which comprised the east end of the lagoon). It is probably one of 

 the three or four commonest sponges in the Marshall Islands. I could not 

 find it at Ponape but suspect it is there. I did find it very rarely at Truk and 

 in the Palaus. 



This species was found largely in very shallow water, from bottoms almost 

 exposed at low tide, to a depth of at least 5 meters. The substratum regularly 

 was dead coral. Young specimens begin as a crust, but the species should 

 definitely be classified as not one of the incrusting type. The crust tends to 

 become thicker and thicker as it becomes older, which is not true of definitely 

 incrusting species, and it soon begins to send up ramose projections which 

 may become quite high. Some projections were found to be at least 50 cm 

 in vertical measurement. These ramose branches usually ranged between 

 1 and 2.5 cm in diameter. 



The color in life was regularly yellow, in a few cases almost orange- 

 yellow ; but upon dying in the air or in alcohol it changed first to purple and 

 finally to black. A conspicuous difference in the time required was noticed 

 from east to west. The many Marshall Island specimens required several 

 hours, say as many as four, for complete change to take place. This change 

 was irregular, some spots becoming black almost at once whereas others re- 

 mained yellow after four hours. In contrast, the specimens from Truk and 

 the Palaus changed in five minutes to the full black color. 



