no. 2073. HOLOTHURIANS FROM NORTHWEST PACIFIC— OHSHIMA. 241 



curved, spiny rods often branched, sometimes X-shaped. Very 

 rarely, simple, spiny, unbranched rods are found besides the four- 

 rayed spicules. In genital tubes are found slender X-shaped bodies 

 like those known in P. intermedia Ludwig. Their arms measure 100- 

 340//. Calcareous ring consists of 5 radial segments only, 1 mm. in 

 length, with numerous, branched projections. Stone-canal rather 

 large, not specially strengthened with spicules, opens externally 

 about midway between tentacular crown and dorsal brim. Polian 

 vesicle single. Radial muscles well developed, dorsal pair divided, 

 others simple, midventral one being much more slender. Genital 

 tubes borne on two large branches of the wide duct, which opens near 

 the madreporic aperture. 



P. azorica v. Marenzeller and P. 'purpurea (Theel) are very close to 

 the present species but differ above all in the absence of the lateral 

 brims. P. atrox Theel, P. expansa Kcehler and Vaney, and P. inter- 

 media Ludwig have lateral brims, but differ in shape of spicules. 



I refer the specimen from station 5083 to this species with much 

 doubt. Spicules of this specimen are asymmetrical in having only 

 three vertical processes. Probably this may be a different and unre- 

 corded species. 



Habitat. — Off Kii, Honshu; south of Totomi, Honshu. 



Type.— Cat. No. 34157, U.S.N.M. ' 



Genus ACHLYONlCE Theel. 



32. ACHLYONICE MONACTINICA, new species. 

 Plate 9, figs, lla-c. 



Station 4974. One specimen. 



Station 5084. Sixteen specimens. 

 Body elongated, length 100 mm., about 3.5-4 times the width. 

 Anterior end strongly bent ventrad, mouth terminal but ventral, anus 

 slightly turned dorsad. Dorsum much vaulted, but flattened at the 

 posterior part. Color uniformly pale white, integument opaque, 

 smooth to the touch. Tentacles 12, nonretractile, connected with 

 one another by a membranous fold of skin, except the smaller 4 of the 

 ventral side, which are free. Tips of tentacles light yellow. On the 

 dorsal side of the necklike part there is a transverse fold of skin with 

 two pairs of papillae. The papillae of the anterior (median) pair are 

 short and project but little from the skin fold as a very short conical 

 process, while the second pair, which are posterolateral to the former, 

 are 15 mm. in their free parts. There are two more pairs of minute 

 papillae behind the large ones just mentioned. Pedicels confined to 

 the posterior half of body, in a row along each side of ventrum, 10-13 

 in each row, most commonly 11. The anteriormost are largest, 7.5 

 mm. long and 4 mm. across. The only deposits are slender, un- 

 branched rods with some spines (pi. 9, fig. lie); though very rarely 

 59758°— Proc.N.M.voL.48— 14 16 



