PACIFIC TUNICATA OF U.S. NATIONAL MUSEUM 117 



are well developed on thorax, although exact number of muscles can- 

 not be given here because of strongly contracted state of specimen. 

 Longitudinal muscles go onto abdomen being united into two pairs of 

 longitudinal muscle bands. About 10 stigmata in each of three rows; 

 many yellowdsh corpuscles found deposited between the stigmata, 

 probably branchial sac orange red when the animal was alive. About 

 20 tentacles, ciliated groove elliptical and situated longitudinally, 

 dorsal languets tongue-shaped. Hind stomach and midintestine well 

 defined, about I14 times the length of stomach when measured together. 

 Proximal end of rectum constricted markedly from midintestine, but 

 no caeca formed there. Circumintestinal gland consists of about a 

 dozen fine tubules extending from level of pyloric end of stomach 

 anteriorly for a distance of about twice as long as stomach. Two 

 vesicles, one much larger, beside rectum at proximal portion of cir- 

 cumintestmal gland. Anus bilobed, opens at level of second trans- 

 verse vessel. Ovary situated on left side of intestinal loop near level 

 of pyloric end of stomach. Testicular follicles, 12-29 in examined 

 zooids, crowded inside intestinal loop posterior to middle of stomach 

 and divided into dorsal and ventral groups, dorsal group usually 

 larger than ventral. This feature can be easily seen on right side of 

 loop. Usually one or two embryos found in incubatory chamber. 



Kemarks. — The appearance of the present colony superficially re- 

 sembles Eudistoma rigkla Tokioka, but the color and hardness of the 

 test difi^er distinctly between these two forms. Moreover, the range 

 of the tubular circumintestinal gland is much narrower in E. rigkla 

 than in the present specimen. Eudistoma snakabrl Tokioka also re- 

 sembles the present form in the general structure of zooid, although the 

 shape of the stomach differs considerably. Also the colony of the 

 former carries sand grains over the surface and contams them within 

 the test. EudistoTYia angolanum (Michaelsen) shows a very close re- 

 semblance to the present specimen in the structure of zooid, although 

 the colony carries foreign matter within the test, sparsely in the upper 

 layer, and more densely in the bottom layer. Thus, it is very possible 

 that the present colony may represent an unusual state of E. ango- 

 lanum^ in which sand grains are missing within the test due to some 

 unknown cause. 



49. Eudistoma rubruni Tokioka 



Figure 41?^ 

 Eudistoma rubra Tokioka, 1954a, p. 252, fig. 2 ; pi. 28, figs. 2-G. 



MATERIAL EXAMINED 



Gilbert Islands : Onotoa Atoll ; P. E. Cloud, sta. GOC-55. One colony (USNM 

 11477). 



Descripiton. — There is some doubt of the present identification. A 

 single roughly cylindrical colony attached to the substratum some- 

 what obliquely was examined. It is 12 mm. long, 8 mm. in diameter 



