182 THE ECHINODERMS OF TORRES STRAIT. 
Holothuria subverta! sp. nov. 
(Plate 38, Figures 25 to 32.) 
Length about 100 mm.; breadth 23 mm.; vertical diameter about 12 mm. Body 
notably depressed, widest posterior to middle and narrowed towards each end, well covered 
with papillz and pedicels; no hard-and-fast line can be drawn between these two sorts of 
appendages as occurring in suwbveria; true pedicels (simple cylindrical, truncate outgrowths) 
are relatively rare, but true papille (elongatedly conical, pointed outgrowths) are also rare; 
most of the appendages are conical for the basal half and cylindrical and truncate distally; 
ventrally they are mostly about 2 mm. long, in 8 to 10 irregular series, the outermost series 
on each side being situated on the well-marked margin between the dorsal and ventral 
surfaces; among these longer papille-pedicels are scattered a few small pedicels which 
lack the conical base; dorsally the appendages are smaller (as a rule), more numerous and 
much less evidently in series; many are more pointed distally; the ventral surface is quite 
clean, but the dorsal surface seems to have much fine dirt adherent to it. Tentacles 20, 
small and very short. Calcareous ring rather stout; radial pieces deeply forked anteriorly, 
about 2 mm. high by 1.75 mm. wide; interradial pieces much smaller, with an anterior 
pointed projection, 1.2 mm. wide, 0.70 mm. high at the sides, and 1 mm. at the center; neither 
radial nor interradial pieces are markedly concave posteriorly. Polian vessels 2, 7 to 8 mm. 
long. Madreporic canal single, free, 7 to 8 mm. long. Cuvier’s organs very well developed, 
forming a compact tuft of thick whitish tubules at the base of the respiratory tree. 
Calcareous particles in tentacles, papillee, and body-wall exceedingly numerous, and 
while they are easily grouped as supporting rods, buttons, and tables, they are very variable 
indeed. Tables 0.035 to 0.100 mm. across the disk, with spires 0.040 to 0.140 mm. high 
and 0.025 to 0.030 mm. square at top; disk (pl. 38, fig. 27) squarish, with smooth margins, 
a large central hole and about 8 marginal perforations, of which the 4 corner ones are 
smaller than the 4 which lie between them; spire (pl. 38, fig. 26) with 1 to 6 cross-bars, 
but usually with several; only a few small, stumpy tables (pl. 38, fig. 30) have but a single 
cross-bar; the tables form a single layer all over the animal; they are lower and more 
stumpy dorsally than ventrally, and are highest (pl. 38, fig. 29) and most slender in the 
papillez. Buttons 0.030 to 0.080 mm. long, with the width half as much or less; typically 
there are 3 pairs of perforations of approximately equal size (pl. 38, fig. 31), but some- 
times the pair at each end of the button is greatly reduced, leaving a large perforation on 
each side at the middle of the button, and 2 little round holes near each end; on the 
other hand, buttons occur with small holes at each end in addition to the usual 6 large per- 
forations (pl. 38, fig. 32); buttons smooth or knobbed, but usually with 12 to 16 knobs 
on each surface; sometimes on the smallest plates only 2 distinct knobs are present on each 
side, these being at the ends of the bar separating the median pair of perforations; ventrally 
there are few knobs on the buttons, commonly none along the margins, but the dorsal 
buttons are usually very fully knobbed. Supporting rods of pedicels (pl. 38, fig. 25), 
typically about 0.150 mm. long, expanded and with 1 to 4 perforations at each end, and also 
expanded at the middle with 1 or 2 relatively large perforations there, on each side of the 
long axis; such rods intergrade, however, especially near base of pedicels, with the true 
buttons. Supporting rods of tentacles simply smooth, slightly curved rods, with the ends 
neither expanded nor branched; they are 0.075 to 0.125 mm. long. Terminal plates well 
developed in pedicels, while at the tips of some of the more pointed dorsal papille are 
minute, reticulated spheres, one sphere to each papilla, apparently a modified terminal 
plate. Color dull gray, brownish dorsally because of dirt; pedicel-papillee white or whitish, 
ventrally contrasting evidently with the ground-color but dorsally obscured by dirt; 
tentacles very light. 
1Subvertus = upside-down, in reference to the ease with which the lower surface may be mistaken for the upper. 
