MUSEUM OF COMPARATIVE ZOOLOGY. 43 



in a strong spine-ridge. Upper arm-plates transverse oval, twice as broad as 

 long, slightly swollen, each surrounded by a single line of rounded granules, 

 which are broader than long. Disk round and thick, with a flat top, covered 

 with thin, variously shaped scales, which, near the margin, are obscured by thick 

 skin ; those of the centre small, round, and arranged in a rosette ; those farther 

 out, larger and elongated, arranged in three or four rows between the radial 

 shields in the interbrachial spaces, where they are beset with a few scattered 

 grains, which at the margin become much more numerous and larger, and 

 appear as very short spines. Interbrachial spaces below covered with a few 

 grain-like spines. Radial shields large, pear-seed shaped, much longer than 

 wide, separated usually by a line of two large and two sm'all scales. Genital 

 openings large and extending about two thirds the distance to the margin. 

 Five, rarely six, stout cylindrical, blunt, tapering arm-spines, whereof the second 

 and third are stoutest, and as long as one and a half arm-joints. One, and on 

 the first two joints sometimes two, small, rounded tentacle-scales. At tip of 

 arm are four slender spines, of which the lowest takes the form of a flat, long, 

 three-toothed hook, as elsewhere in this genus. Color in alcohol, above, L'ght 

 pink ; below, pale straw. 



Prof. P. Martin Duncan has recently published (Linnean Soc. Journ. 

 Zo5l., XIV. 460, 479) an Ophiuran, Ophiolepis mlrahilis, of which he re- 

 marks : " This common species has the disk of Ophiolepis as diagnosed by 

 Miiller and Troschel, that is to say, the scales, which are of good size, and the 

 large radial shields, are environed by rows of small scales as by belts. But the 

 upper arm-plates have also the supplementary rows of small scales around them, 

 and there are also large accessory side pieces. Moreover, there are hooks on 

 the side arm-plates. This mixture of Ophiolepian and Ophiopholian characters 

 is very interesting ; and this species, I consider, renders the abolition of Ophio- 

 pholis as a genus inevitable." 



The meaning of this passage is not quite clear, because Miiller and Troschel 

 (Syst. d. Asterid., p. 89) diagnosed, not the whole genus, but only the first sec- 

 tion of it, as having belts of scales round the disk plates (e. g. 0. cincta). To 

 this section Ophiolepis has been restricted. The third section they described 

 as having spines on the scales. This last is Ophiopholis, a genus now rec- 

 ognized as quite remote from the true Ophiolepis, which stands nearer Ophio- 

 glypha, Pectinura, &c., while Ophiopholis approaches the Amphiurce through 

 Ophiactis asperula. It is evident that Ophiolepis mirahilis is a true Ophiopholis, 

 lacking none of its characters, and standing quite near the typical O. aculeata. 

 The fact that certain small scales surround larger ones is not here of generic 

 importance, and probably results from the young stage of the specimen, which, 

 to judge from the figures, had a disk not exceeding 4 mm. in diameter. Ophio- 

 pholis japonica difl^ers from the old species as well as from O. mirahilis in its 

 more slender arm-spines, and in having the radial shields and much of the 

 upper disk free of grains or spines. 



Station 235, 565 fathoms, 1 specimen. Station 236, 420-775 fathoms, 

 3 specimens. 



