A 



198 THE SPONGES OF THE WEST-CENTRAL PACIFIC 



U.S.N.M. No. 22855, My No. M. 149, collected July 7, 1949, by diver at 



Ebon Atoll in the southeast portion of the lagoon. The depth was 2 



meters, and the substrate was dead coral. 

 U.S.N.M. No. 22844, My No. M. 135, collected July 5, 1949, by diver at Ebon 



Atoll from the Pearl Pool in the west portion of the lagoon. The depth 



was 5 meters, and the substrate was dead coral. 

 U.S.N.M. No. 22867, My No. M. 161, collected July 11, 1949, by diver at 



Likiep Atoll from the east portion of the lagoon near Lado Islet. The 



depth was 5 meters, and the substrate was dead coral. 

 U.S.N.M. No. 22881, My No. 180, collected August 1, 1949, by diver in 



eastern Ponape (Matalanim) from a reef near an entrance to the lagoon. 



The depth was 5 meters, and the substrate was dead coral. 

 U.S.N.M. No. 22891, My No. M. 191, collected August 3, 1949, by diver in 



Southwest Ponape (Kiti) near Kepara Islet from a reef in the lagoon 



near the open ocean. The depth was 3 meters, and the substrate was of 



dead coral. 



This species is extremely abundant throughout the Marshall Islands and 

 Ponape. Unless it was buried in sand, almost any specimen of dead coral 

 brought to the surface may be found to have either a small or a large incrusta- 

 tion of this Spirastrella on the under side. 



This species is regularly incrusting, about 1 mm thick (never much less 

 nor more than this). Lateral growth is indefinite, oftentimes 15 or 20 cm, 

 but the majority of specimens are coin-sized. 



The color in life was always red but might have slight brownish tinges, 

 possibly due to the presence of small green plant forms. The consistency was 

 soft, almost colloidal. 



The surface is smooth and marked by conspicuous river-like patterns, 

 which represent large subdermal canals. These begin as myriads of small 

 canals, which flow together into fewer and larger ones and doubtlessly ter- 



C 





Text Figure No. 134. Spicules of Spirastrella potamophera. A: Two of the rylostyles, 

 X 182. B: Larger size spiraster, X 782. C: Two spirasters of the smaller size range, 



X 782. 



