Dr. J. E. Gray on the " Glass-Rope " Hyalonema. 291 



of the ' Histoire Naturelle des Coralliaires, ou Polypes propre- 

 ment ' etc., observe, " Nous sommes portes k croire qu^il fauclra 

 ranger dans ce sous-ordre des Zoanthaires sclerodermes, k la suite 

 des Antipathiens, un zoophyte tres-remarquable des mers du 

 Japon, qui se compose d'un ccenenchyme cortical, renfermant , 

 Hn faisceau de baguettes siliceuses tres-greles, tordu en spirale 

 comme une corde dont les crius seraient faits avec du cristal. Le 

 ccenenchyme est farci de petits spicules, et porte des tubercules 

 deprimes dont le sommet est perfore et parait etre le calice du 

 polype. Souvent Taxe fascicule se denude par sa base, et se 

 trouve implante dans une eponge; mais, d'apres M. Gray, celle-ci 

 y est etraugere. Je dois ajouter cependant que suivant M.Valen- 

 ciennes ce singulier zoophyte appartiendrait k la famille des 

 eponges" (p. 324). And in their Monograph of British Fossil 

 Corals, p. Ixxxi, they observe, " The genus Hyalonema established 

 by Mr. Gray is also referred by some zoologists to the tribe 

 GorgonicB; but the recent observations of M. Valenciennes tend 

 to establish that the fasciculus of siliceous thread which consti- 

 tutes the axis of this singular production belongs to the class of 

 Spongia; and the polypes which we have observed in a dried 

 state on different parts of the axis appear to be parasites belong- 

 ing to the order Zoantharia.'* 



In 1860 Professor Max Schultze published the elaborate essay 

 above quoted ; and he regards the rope of siliceous spicula as 

 part of a sponge, and the polypes as parasitic on it, calling the 

 polypes " Polythoa fatua mihi " (pp. 28 & 42). 



l)r. Bowerbank, adopting the same view, in his lately pub- 

 lished work on British Sponges, gives the following as the ge- 

 neric character of the genus Hyalonema : — " Skeleton an inde- 

 finite network of siliceous spicula, composed of separate elon- 

 gated fasciculi, reposing on a continuous membrane, having the 

 middle of the sponge perforated vertically by an extended spiral 

 fasciculus of single elongated and very large spicula, forming 

 an axial skeleton of a columnar cloacal system " (vol. ii. p, 9). 



I must confess that I do not understand this description. If 

 the fasciculus of fibres is " a cloacal system," how is it that the 

 fibres have no connexion with the sponges, but are separated 

 from the spiral fascicle by . a hardened coat most closely 

 attached to the elongated spicula ? And if the rope is entirely 

 covered with the zoophytes, as we have every reason to believe 

 is the case, and as M. Brandt's figures show, what is the use of 

 a " cloacal system^' which has no exit ? It has occurred to me, 

 as Dr. Bowerbank does not take any notice of the polype-bear- 

 ing bark that covers the axis, that he confounds the polypes 

 with the oscula of the sponge, and, believing them to be oscula, 

 thinks they are the exits from the cloacal system he describes. 



