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

512 COLLECTIONS FROM THE WESTERN INDIAN OCEAN.Neoplax ophiodes. (Plate XLV. figs, a-e.)Disk pentagonal and small ; arms narrow, elongated, having tliogeneral appearance of being somewhat constricted between eachjoint, owing, probably, to the mode of attachment of the spines tothe edge of the side arm-plates. Granules on the disk rather large,sparse, scattered, sometimes almost glassy in appearance ; at the edgeof the disk thej- are more closely packed and form a pretty definite rowof bounding granules. Very few granules on the actinal surface.Mouth-plates oval, a good deal broader than long, the side mouthshieldslying across them, so as almost, or altogether, to meet in themiddle line. Five mouth-papillce, four close together, the fifthclose to its fellow of tho opposite sidel Three or four pretty strongteeth.Though the genital slits are ordinarily long, the bridge separatingthe fellows of a pair is of a fair breadth ;genital scale prominent.On the fourth or fifth joint from the disk there are six smallbut distinct lateral spines, attached to the edge of the lateral plateand further out there may be seven spines. The lowest;spine isthe longest and the most distinct. The upper arm-plates are widestalong their proximal edge, the sides slope inwards, and the distaledge is much narrower. The most distinctive character in thelower arm-plates appears to be the excavation on the distal edge.The tentacle-scale is single, small, and at times, indeed, appears tobe absent.Diam. of disk 11-5, 8. Length of arm (probable), 60, 40 millim.Coloration : the three specimens exhibit some ditferences, but areall brownish above and of a lighter hue below ; several arm-jointsare, here and there, darker than those just in front of or behindthem.All the three specimens were found at Darros Island, Amirantegroup, at a depth of 22 fms.