no. 2073. HOLOTHURIANS FROM NORTHWEST PACIFIC— OHSHIMA. 223 



■much clustered in that species. The presence of as many as 10 or 

 more Polian vesicles is a character which distinguishes the new 

 species from all the others. 



Habitat. — South of Hokkaido; off Ojika Peninsula, Honshu. 



Type.— Cat. No. 34143, U.S.N.M. 



5. SYNALLACTES GILBERTI, new species. 

 Plate 8, figs. 2a, b. 



Station 4979. Two specimens. 



Station 5084. Three specimens. 

 Body 80 mm. long and 20 mm. broad. Mouth subventral, anus 

 terminal or turned dorsad. Color light gray with slight greenish 

 tinge. Skin smooth to the touch, with thick gelatinous subcuta- 

 neous tissue. Tentacles 20. Pedicels of the odd ambulacrum rather 

 scattered, not exceeding 25 in number, arranged in a zigzag or double 

 row. Each ventrolateral ambulacrum has numerous pedicels which 

 form a zigzag row along the margin of sole. There are 4 rows of 

 papillae on dorsum, each papilla being situated on a conical wart. 

 Papillae of the outer rows are larger than those of the inner, the wart 

 measuring 4 mm. across and the free filamentous part attaining a 

 length of 7 mm. Each of these rows consists of 12-15 papillae. 

 Much smaller papillae belonging to ventrolateral ambulacra form a 

 marginal row along each side. Scattered among these are found 

 appendages of another kind. These are what have been called 

 "Saugfusschen im engeren Sinne" (Ludwig), or "low whitish warts 7 ' 

 (Theel), or "fungiform papillae" (Mitsukuri). They measure 0.55- 

 1.20 mm. in diameter. Cruciform table-like deposits are uniformly 

 distributed in general perisome. The arms do not meet in one point, 

 but diverge from the ends of a short rod, thus becoming bilaterally 

 symmetrical (pi. 8, fig. 2a). Each arm is perforated with a small 

 hole at the end. Spire is solid and high; the end is divided into 3 

 long processes which unite again at some distance from the apex and 

 thus give rise to a slitlike hole (fig. 2b). The deposits of ventrum 

 vary in diameter between 60 and 100//, with a mean of about 80/z, 

 and the spire 65-70/1 high. Those of dorsum are 100/* in diameter, 

 ranging 77-140/*, spire 100/* high. Walls of pedicels and papillae 

 are beset with similar deposits, and a few curved rods are found near 

 tips of pedicels. End-plate is well developed in pedicels but repre- 

 sented by irregularly branched rods in papillae. The fungiform 

 papillae are destitute of tables but a branched body represents the 

 end-plate. Supporting rods of tentacles are spinous and arcuate, 

 often armed with some irregular branches. Calcareous ring con- 

 sists of 10 weakly calcified segments. Polian vesicle single; stone- 

 canal minute, with scattered, irregular latticed deposits in its wall. 

 Genital tubes few in number, branched once or twice. 



