9 JEch. 
ECHINODERMATA. 
sp. n., p. 5, pi. i. figs. 4-10 & 16, 82 faths., off Barbadoes. 0. pellucidus, 
sp. n., p. 6, pi. i. figs. 11-15, near Fiji, 1350 faths. 
Ophiocymhium. “ Disk flat, and covered with delicate overlapping 
scales, without radial shields externally visible. It overlies and is scarcely 
attached to the arms, and there seem to bo no genital openings. Arm- 
spines along outer edge of side arm-plates. On jaw-plate, a tuft of small 
spines, which correspond to teeth and tooth-papillae. Mouth-papillae 
squarish, and arranged in a close line. Tentacle-pores very large ; those 
of the second mouth-tentacles set in a socket much like the rest.” 0. 
cavernosiim, sp. n., p. 7, east of Kerguelen, 1950 faths. 
OphiocJiytra. “ Disk covered with little overlapping scales and small 
radial shields; teeth; no tooth-papillao ; a lino of squarish close-set 
mouth-papillae on either side ; large side arm-plates, which meet above 
and below and bear on their outer edge small spines, which, however, 
stand at nearly a right angle to the arm.” For 0. epigrus, sp. n., ‘ Chal- 
lenger' station 276, near Low Archipelago, 2350 fathoms. 
Opliiamhix. “Disk fiat, arms wide and flat, and both beset above with 
sharp grains, or spines ; no radial shields or upper arm-plates externally 
visible ; small, sharp mouth-papillae and teeth, no tooth-papillae ; tentacle- 
pores very large ; side arm-plates widely separated above and below, but 
occupying a considerable part of under surface of arm ; arm-spines 
translucent, hollow, and with an uneven surface.” For 0. aculeatus, sp. n., 
‘ Challenger’ station 175, near Fiji Islands, 1350 fathoms. 
Also, as new species : — 
Ophiacantha placentigera, station 175, 1350 fathoms. 
Ophiopeza cequalis, station 219, N.B. of New Guinea, 152 fathoms. 
FolyphoUs, g. n. For P. echinata, sp. n., Duncan (12). 
UemiphoUs luallicldj sp. n., id. (13). 
Amphiura parva, sp. n., Hutton (20). 
Ophiarachna armata, sp. n., Troschel, SB. Ver. Rheinl. [1879] p. 137, 
Mauritius ; also notes on the genus, pp. 135-138. 
Ophioconis hrevispina, sp. n., Ludwig (21). 
Ophiothrix petersi, sp. n., Studer (36). 
Opthiacantha millespina^ sp. n., Verrill, Bull. U. S. Nat. Mus. ii. p. 203. 
HOLOTHUROIDEA. 
Thdel (38) gives the following definition of the Plasmapoda^ a new 
order of Holothuroidea: — “ Body distinctly bilateral; ambulacra well 
defined ; the lateral ambulacra of the trivium bearing large, slightly 
retractile pedicels, disposed either in a single row, or sometimes in two 
rows, along each side of the ventral surface, and sometimes with another 
series of larger highly elongated not retractile processes, placed externally 
and above the pedicels; pedicels of the two lateral ambulacra symmetrically 
arranged, being more or less distinctly opposed across the ventral sur- 
face ; the odd ambulacrum naked, or very seldom with a few rudimental 
pedicels ; bivium provided with very long, not retractile processes, often 
disposed in one or more rows along each of its ambulacra, and more or 
