no. 2073. HOLOTHURIANS FROM NORTHWEST PACIFIC— OHSHIMA. 273 



directed dorsad, and in longitudinal section toward either end of the 

 body. The free margin bears a vertically directed, rudimentary, 

 spiny process. In the introvert irregularly elongated plates with 

 large holes and slight knobs are present; length, 130-270//, with a 

 mean of 185/i; holes 4-39 in number, averaging 14. Supporting rods 

 of tentacles are arched, narrow plates with several holes and serrated 

 margin, measuring 0.1-0.2 mm. in length. Supporting rods of pedi- 

 cels are rudimentary and sparse, with a few large holes. End plate, 

 of irregular shape, 90-130/* in diameter. It is very difficult to make 

 out the true arrangement of the calcareous ring. Radial segments 

 have 2 or 3 anterior processes, but no posterior prolongations. Some 

 interradial segments seem to be composed of 2 triangular pieces. In 

 general configuration the segments are very much like those of Cucu- 

 maria inflexa Kcehler and Vaney. 1 Polian vesicle and stone-canal 

 single. Retractors inserted 5 mm. from the anterior end of body. 

 Respiratory trees 2, simple, with rudimentary branches in the shape 

 of globular vesicles. Genital tubes unbranched, in 2 tufts. The 

 third limb of the alimentary canal runs along the left side of the odd 

 ambulacrum. 



This species is quite characteristic in the number, form, and relative 

 sizes of its tentacles and in the asymmetry of the calcareous ring. It 

 may be unnatural to refer it to the genus Pseudocucumis; probably a 

 new genus should be formed to include this species and the closely 

 allied Cucumaria digitata Kcehler and Vaney. 



Habitat. — Off Koshiki Islands, west of Kyushu. 



Type.— Cat. No. 34175, U.S.N.M. 



76. PSEUDOCUCUMIS WATASEI, new species. 

 Plate 10, figs. 25a, b. 



Station 5069. Eight specimens. 

 Body cylindrical or spindle-shaped, measuring 21 mm. in length, 

 exclusive of the introvert, and 8 mm. in diameter. Color pale white 

 to dirty brown; integument thin and somewhat stiff, slightly rough 

 to the touch. Tentacles 20, of 3 different sizes. The largest 10, one 

 pair to each interradius, alternate with 5 radially situated pairs, 

 which are of 2 sizes. In the paired radii the smaller one is situated 

 ventrally to the larger, and in the odd radius, at the left. Pedicels 

 arranged regularly in 2 rows in each ambulacrum both in trivium and 

 bivium, not crowded. Inter ambulacra totally devoid of pedicels. 

 General perisome uniformly beset with numerous tables (pi. 10, 

 figs. 25a, b) . Disk round or slightly elliptic, with entire margin. Cen- 

 tral hole large, usually with an X-shaped span on the underside (fig. 

 25&). Peripheral holes 8 in number normally, but may increase to 

 1 1 . Spire consists of 2 converging pillars, united by a crossbeam and 



1 Les Holothuries li Morales, 1908, pi. 2, fig. 9. 

 59758°— Proc.N.M. vol.48— 14 18 



