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THE VOYAGE OF H.M.S. CHALLENGER. 
dichotomously branched. A bundle of a few rather large, simple Cuvierian organs is 
present. 
The deposits are not very well developed. The buttons (PL VIII. fig. 9, h) are very 
irregularly formed, with from two to six holes ; their length is as much as 0‘03 mm. Near 
the ambulacral appendages the buttons often become larger and the number of holes 
greater (PI. YIII. fig. 9, c). The tables (PI. VIII. fig. 9, a) have the disk small, often 
rudimentary and confined to a simple ring ; in the larger tables the disk measures 
0'03 mm. in diameter. The spire of the tables is more or less rudimentary; compare 
the figures. The pedicels are strengthened by perforated rods or rod-like plates 
(PI. VIII. fig. 9, d), with the holes often arranged in two longitudinal series. In the 
papillae, which have a very poorly-developed terminal plate, the deposits seem to be a 
little more rod-like than in the pedicels. 
Holothuria fusco-rubra, n. sp. (PI. VII. fig. 2). 
Habitat. — Sandwich Islands ; a single specimen. 
This specimen seems to be nearly allied to the preceding species, with which it agrees 
in nearly all respects. I may therefore refer to the description of Ludwig, while I here only 
point out the differences. When fully extended it attains a considerable size ; its colour 
is uniformly dark browm inclining to reddish, and the brown rings of the pedicels and 
papillae are totally absent. The pedicels are much more numerous than the dorsal 
papillae, which are comparatively few, so that an obvious line of demarcation is visible 
between the dorsal and ventral surfaces. There are also some slight differences in the 
deposits. Thus the disks of the tables (PL VII. fig. 2, a), about 0"06 mm. in diameter, 
have the margin very uneven and often provided with spines. The spire of the tables is 
totally absent or reduced to a few short spines (commonly four), the apices of which are 
very seldom joined by transverse beams. When such transverse beams were present, I 
never found any teeth, characteristic of the tables in other Holothurians. The most 
incompletely developed buttons (PL VII. fig. 2, b) have a length of about 0‘06 mm. ; 
in a complete state the buttons are pierced by six holes in two rows. In the ambulacral 
appendages longer buttons with more holes are to be found. The pedicels, which are 
more crowded than the papillae, bear near their ends fenestrated irregular plates (PL VII. 
fig. 2, c), and the scattered small dorsal papillae are strengthened by slightly curved and 
spinous rods. The Cuvierian tubes are very well developed. 
So far as I can see, this form cannot be referred to any previously described species, 
though it bears the closest resemblance to several of them, especially to Holothuria 
curiosa, Holothuria vagabunda, and Holothuria lagoena. 
