36 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



non Amaroucium multiplicatum Tokioka, 1953a, p. 180, pi. 5, figs. 1-4. ( = 

 Aniaroucium sagamiensc Tokioka, new species. See below, p. 40.) 



MATERIAL EXAMINED 



Palau Islands : Urukthapel Is., reef south of Ngaremdiu ; GVF sta. 227, one 

 colony (USNM 11446). — Eil Malk, fringing reef of small island in lagoon; 

 GVF sta. 252, four colonies (USNM 11428).— Ngerkuid, west of Eil Malk; 

 GVF sta. 261, six colonies (USNM 11394). 



Gilbert Islands: Onotoa Atoll; A. H. Banner, sta. B-3, 11 colonies (USNM 

 11485) ; sta. B^, 3 colonies (USNM 11495) and 1 colony (USNM 11496). 



Description. — The largest of 15 specimens from Onotoa Atoll is 

 16 mm. X 12 mm. in extent; their thickness varies from 2 to 9 mm. 

 Of the 11 colonies from the Palau Islands, the larger range from 23 

 mm. X 10 mm. to 17 mm. X 14 mm. in extent, and from 4 to 9 mm. 

 in thickness; 6 of them are attached to pieces of Halimeda. The 

 small colonies roughly massive, the larger ones sometimes rather en- 

 crusted like some forms of Didemnidae and Botryllidae. Surface 

 smooth and free of foreign matter and glistens in some small colonies 

 from Palau Islands. The system of arrangement of the zooids is 

 roughly stellate in smaller colonies and usually consists of 8-9 zooids 

 surrounding one central common cloacal aperture, although it is not 

 so regularly formed. In larger colonies, however, the system is rather 

 indistinct and resembles that usually found in common species of the 

 genus of Botrylloides. In such colonies two or more common cloacal 

 apertures are on the surface. The apertures vary in size, some large 

 ones attaining 6 mm. in long diameter; the margin of the apertures 

 may be smooth in some specimens, although it is fringed with some 

 small prominences in others. 



Test soft, gelatinous, translucent and milky white, pale yellowish 

 to reddish brown or dark purplish, densely sprinkled with purplish 

 black pigment. No sand grains found in test. Whitish fecal pellets 

 in lacunar system seen through test. Zooids faintly colored in pale 

 brown, reddish brown, or sprinkled with purplish-black pigment in 

 various degrees. Thorax heavily pigmented in some zooids, abdo- 

 men usually pigmented very lightly. Both dorsal and ventral sides 

 of esophagus, cardiac portion of stomach, and proximal portion of 

 rectum rather darkly pigmented in some zooids. Zooids usually 4.5 

 to 6 mm. in length, although only 1.5 mm. in length in a strongly 

 contracted state; extended thoraces may reach 3 mm. in length. 

 Zooids usually situated perpendicularly in thicker colonies, but some- 

 what obliquely in thinner colonies. Abdomen one- fourth to one-third 

 the length of thorax in a contracted state, but nearly equal to or longer 

 than thorax in some wholly extended zooids, even attaining 1.5 times 

 the length of thorax. Postabdomen usually equal to or slightly longer 

 than abdomen, although in immature stages containing no gonads 

 it is much shorter (about one-third of the abdomen). In many colo- 

 nies the postabdomen is placed obliquely or horizontally. Thus, in 



