Report on the zoological collections made in the Indo-Pacific Ocean ...

ECHINODEEMATA. 147Hololhurians it is especially necessary to remember the words ofFabricius, " Tn spiritii viiii mire dcformatiir, ita ut non pro eademhabeatur '**. The remarkable spicules arc, however, an exact copyof those figured by Semper ; and there seems to be no good reason forerecting on it a new species.Port Jackson, 0-5 fms.3. Cucumaria semperi. (Plate IX. fig. A.)Body elongated, 5-sided ; suckers regularly arranged in two rows,except at the two ends of the body ; the suckers darker than theother parts, being almost black ; the rest of the body of a mulattotint (in spirit), or slate-grey, or whitish. Body widest in the middle.Length 36, 25 millim. ;greatest breadth 10, 8"5 millim.Ketractors inserted at a little more than one third of the wholelength from the anterior end ; Polian vesicle large ; calcareous ringlong,and composed of a number of pieces, as in G. conjimgens orC. citrea. Genital tubes delicate, about 6 millim. long, attached tothe mesentery at about the middle of the body.The supporting-rods in the suckers are not unlike folding eyeglassesin form, and are somewhat similar to those of Ocniis pygmcvus ;the plates in the integument are spherical, the framework very delicateand consisting, as seen in a surface view, of a central bar connectedat cither end with the peripheral encircling piece by twobars making an acute angle with one another. They are presentin great numbers.Port Denison ; Torres Straits.4. Ocnus, sp.A single specimen of what is apparently an undescribed specieais in the collection ; but its form is so characteristic that I have notthought it right to injure it in any way. It is distinguished externallyby the soft interspaces in the integument, the greyish-whitecolour, and the elongated narrow form of the body.Port Darwin, 12 fms.5. ColocMrus tuberculosus. (Plate IX. fig. B.)Colochirus anceps, Semper, Hoi. pp. 57, 239, iblqiie citata.There is a very large series of this species, and the specimensdiffer very considerably among themselves, not only in appearancebut in the extent to which the colouring-matter has been dissolvedout ; only one retains any indication of the red pigment. Thevariations exhibited by the specimens as they have come to theMuseum (some being quite white, others slate- grey, and others* Fauna Groenl, p. 354.i2