NO. 1558. NORTH PACIFIC HOLOTHURIANS— EDWARDS. 61 



9. CUCUMARIA JAPONICA Semper, 1868. 



1868. Cucumaria japonica Semper, p. 236. 



1885. Cucumaria japonica Lampert, p. 143. 



1886. Cucumaria japonica Theel, p. 110. 

 1900. Cucrimaria japonica Ludwig, p. 143. 

 1902. Cucumaria japonica Clark, p. 562. 



June 29, 1903.— Three specimens; Station 1205; lat. 18° 8' 10" N., 

 long. 122° 11' 18" W.; 15 to 2() fathoms; bottom, temperature 50.8°, 

 rock, shells. August 21. — One specimen; Station 1802; off Shakan, 

 Sumner Strait, southeast Alaska; 169 to 212 fathoms; bottom, tem- 

 perature 41.2°, blue mud. Without data — two specimens. 



She in niillimeters. — Introvert extended; length: specimens a, 55; 

 J, 170; greatest diameter, «, 19; ?>, 38; introvert retracted, length, c, 

 21; c/, 33; e, 10; f, 170; greatest diameter, c, 15; d, 19; e^ 20; /, 65. 

 Individuals h and _/ may be taken as adult and the others as 3'oung. 



Color. — Dark, or light, tint of ecru-dral). c, heliotrope-purple, 

 from which as a natural color, the ecru-dral) might result after loss 

 of color in alcohol. 



Spicules ofhody wall. — Perforated plates of irregular form and size. 

 In most of the specimens, as shown in sections, the large, radially 

 placed, perforated plates are massed near the opening of the cloaca, as 

 described by Semper, 1868 (Plate XXXIX, fig. 3). Clark, 1902, did 

 not find these large plates in his four specimens, which otherwise agree 

 with the descriptions given by Semper, 1868, and Lampert, 1885. 



Calcareous ring. — In form like frondosa., but very delicate and 

 generally greatly reduced, not, however, to the mere vestige described 

 by Semper. 



Polian 'Vesicle. — Five specimens with one Polian vesicle, longer than 

 the body, the terminal portion turned forward and coiled among the 

 gonad tubes and branches of the respiratory trees. Length in !>., 200 

 mm. ; /', 351 mm. Since usually but one Polian vesicle has been given, 

 it is worthy of note that e has 1, one in the right ventral radius, 

 one either side of the mid- ventral radius, and one in the left dorsal 

 interradius. 



Stone canals. — Length in millimeters. — As generally twisted, 3 ; when 

 straightened, 5; madreporite, 1. Numher and location. — </, 5, in right 

 and left tufts at edge of base of Polian vesicle; 6?, 6, around base of 

 Polian vesicle; e, 9; c^ 18, scattered around oral canal; />, 95; /', 110, 

 closely crowded in a row around the posterior margin of the entire 

 oral canal. This increase in number accompanies growth, which is 

 strikingly demonstrated in the large number of canals in the adult. 

 This fact I have shown for other Holothurians in a recent paper 

 ( Edwards, 1905). Form. — Simple, or distally bifid or trifid, each branch 

 bearing a small madreporite. Stone canal twisted, sometimes two 

 twisted together, or, again, two may be united at the base. 



