NO. 1555. //.l)r.l//.I.V IIOLOTHUIUANS— FISHER. 661 



HOLOTHURIA FUSCO-RUBRA Theel. 



Plate l.XVIII, fig.s. 8. 'ia-e 



Holothuria fusro-riihrd Tiieei., Challenger Holotluirioidea, Pt. 2, 1886, p. 182, 

 pi. VII, tig. 2. 



General form robu.st, subcylindrical. Moutli terminal, directed 

 somewhat ventrally, .surrounded by a slight collar. Anus terminal. 

 Tentacles 20, rather long. Dorsal and ventral surfaces well differen- 

 tiated, the former with rather well-spaced papilUx?, the latter with 

 crowded pedicels. In one specimen an indistinct indication of serial 

 arrangement is present near the hinder end of the l)ody. Bod}- wall 

 thinner than usual in the genus. Deposits: Incomplete tables with a 

 spinous rimmed disk and rudimentary spire; occasionall}' the latter is 

 entirel}^ absent; button.s as a rule incomplete; when complete usuall}" 

 asymmetrical with six or seven holes. Larger buttons are present 

 near the tips of pedicels. Well-developed Cuvierian organs. Color 

 in alcohol purplish brown to a distinct dull magenta in a young 

 example. Length, about 11(» nun.; tentacles 10 mm. long. 



Loealities. — Laysan Island, reef (0 specimens); Necker Island (1 

 specimen); Hanalei. Kauai (1 ^, no calcareous deposits). 



Most of the specimens are in a l)ad state of contractron, so that it is 

 not possible to give many details of the external appearance. The 

 pa})illa^ appear to be slightly larger than the pedicels. Those near the 

 tentacles are considerably larger than the rest. The integument is 

 decidedly smooth to the touch, doubtless due to the al)sence of spires 

 to tables or their feeble development. 



The calcareous ring is of the usual form. Folian vcssicle single in 

 the specimen dissected. One madreporic canal is ])ivsent on the right 

 side of the mesentery. 



The disks of the tables vary in diameter from about (1.04.5 to 0.06 

 mm., 0.1 15 to «).055 mm. being the common dimension. The border is 

 uneven and usuall}' spiny. In the smallest tables the disk consists of 

 a simple ring with four spokes meeting at the center. Then two of 

 the crosspieces may have a perforation at the base. There is every 

 gradation from this form to that in which there are numerous perfo- 

 rations about the edge. The simpler disks usually lack the spire, 

 which is almost never complete, even when present. The spire varies 

 from a tiny knob on each crosspiece of the disk to four low rods which 

 are incompletely joined at the summit by transverse pieces. Rarely the 

 crown is complete, when it presents the form of a simple ring with 

 about eight irregular teeth on the border. Tiie latter have no constant 

 occurrence. The principal kinds of tables are figured. The buttons 

 are very incomplete and vary so much that it is difficult to find two 

 alike. They are numerous and are about 0.(H) to 0.07 mm. long. In 

 the ambulacral appendages larger l)uttons with eight or more holes are 



