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Show 1867.] DR. J. E. GRAY ON HYALONEMA LUSITANICUM. 119 The want of more materials makes it impossible to come to any conclusion as to the distinctness of the genera or even of the species. If one may judge from the figure of Professor Brandt, the polypes of the genus Hyalocheeta appear to be on the slender end of the axis of the coil of the coral, as in the Portuguese species. It would be desirable to know whether this form is ever found living in a sponge. The specimen in the British Museum, obtained by Dr. W . Lock-hart in Japan, which has some of the polypes prominent and clustered, has the bark only on the lower, more slender end of the coil, and in this respect agrees to some extent with Professor Brandt's figure. But the slender end of the coil projects like a pencil beyond the bark ; and one is by no means sure that the bark, which is evidently very easily moved on the axis in the living or freshly gathered coral, may not have been slipped down towards that end of the coil ; and I think that this may be the case, as I believe that it was obtained with the other Japanese specimens of H. sieboldii which Dr. Lockhart brought home. In this respect it differs from the Portuguese species and from the Hyalocheeta of Prof. Brandt; for in both of them the bark entirely covers the base of the axis, and evidently belongs to that part of the specimen. 2. HYALOTHRIX. The polypes with forty tentacles in several concentric series, the outer series the largest. The axis, covered to the very base with the polype, bearing bark, and the bark strengthened with cylindrical filiform siliceous spicules, and with a smooth external coat without any imbedded granules. This genus is at once distinguished from Hyalonema by the coral not living with its base immersed in a sponge. It lives evidently free; but how it keeps itself in an erect position so that all the polypes round the axis may obtain food is yet to be discovered. 1. HYALOTHRIX LUSITANICA. Hyalonema lusitanicum, Bocage, P. Z. S. 1864, p. 265, pl. XXII. ; 1865, p. 662 ; Gray, Ann. & Mag. N. H. 1866, xviii. p. 287. Hab. Coast of Portugal (Bocage). B.M. After the study of all the specimens which I have been able to see from Japan, and of the Portuguese specimen, I still adhere to the opinion that I formed when I first described the genus, now more than thirty years ago, and which is so well supported by Prof. Brandt in his carefully prepared and well-studied memoir. I regard Hyalonema as a type of a peculiar family of Corals, formed by zoanthoid polypes, characterized by forming for their support a siliceous axis formed of many thread-like spicules coiled together into a rope-like form, each formed of numerous concentric laminae, and surrounded and separated from one another by the corium of the community of polypes. I am aware that M. Valenciennes has suggested that the rope-like coil or axis in the Japanese species is a part of the sponge, and regards |
