108 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



pale purplish brown. Both apertures round in outline. Abdomen 

 214: to 3 times as long as thorax. About 20 transverse muscles on each 

 side of thorax, but no longitudinal muscles found. Stigmatal rows 

 14-15, about 25 stigmata in each row. Ciliated groove an elliptical 

 opening, slightly elongated longitudinally, 16 tentacles arranged as 

 4 large, 4 medium, 8 small, also minute ones. Dorsal languets large 

 and tongue-shaped, horizontal membranes well developed along re- 

 spective transverse vessels. Cardiac end of stomach situated approxi- 

 mately at level of posterior third of abdomen. Stomach somewhat 

 elongated in outline, its surface might be smooth, although in present 

 preserved specimens a few plication-like longitudinal folds are faintly 

 seen, very probably due to contraction of the animal. Midintestinal 

 portion quite obscure. Anus bilobed, opens at level of last trans- 

 verse vessel of branchial sac. About 25 testicular follicles scattered 

 on left side of intestinal loop posterior to stomach. Ovary situated 

 near center of gonad. 



Distribution. — Formerly known from the Arafura Sea. 



46. Clavelina (Synclavella) gigantea Van Name 



Figure 37 



Not Polycitor giganteus Sluiter, 1019, p. 10, pi. 1, figs. 18-20. 



Clavelina gigantea Van Name (part) 1921, p. 358, fig. 40. — Arnback-Christie- 



Linde, 1925, p. 18.— Van Name, 1945, p. 139, fig. 65 ; pi. 14, fig. 1 ; pi. 16, 



fig. 4. 

 Clavelina oMonga Van Name (part) 1930, p. 450, fig. 24, figure on right. 



MATERIAL EXAMINED 



Gulf of Mexico: Off Dry Tortugas ; 25°34'00" N.. 83°07'00" W., 30 fath. ; 

 Grampus sta. 5078, March 1, 1889. Two colonies (USNM 11781) on crab, Dromi- 

 dia antillcnsis Stimpson (USNINI 29000). 



Description. — As Van Name (1918) states that in colonies of Clave- 

 lina moUuccensis (Sluiter), "not mature and those which appear to 

 have grown under less favorable conditions . . . the zooids are not 

 so completely separate . . ., the anterior part of the zooid only has its 

 own sheath of test, the posterior part being imbedded in a common mass 

 of test," it seems to be necessary to compare Clavelina moUuccensis 

 with some known species of Clavelina {Synclavella) and thus a large 

 (60 mm. high and 36 mm. in diameter), pale yellowish gray, nearly 

 roundish massive colony of Clavelina {Synclavella) gigantea Van 

 Name was chosen for this purpose. The colony is carried on the cara- 

 pace of a dromid crab 22 mm. in carapace length, Droraidia antillen- 

 sis Stimpson, from the West Indies area (crab cat. no. 29000). 

 Also a smaller colony 24 mm. long X 11 mm. wide (USNM 11781), 

 containing only seven zooids, carried on the carapace of an 11 mm. 

 long dromid crab was examined. 



Test gelatinous, rather hard, translucent, the surface nearly smooth ; 

 both branchial and atrial apertures contracted, sunken respectively to 



