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



ques specimens du Japon, n'a pas lieu sur aucun des exemplaires 

 du Portugal ;" and he further observes that the thin basal por- 

 tion of the axis which is inserted in the sponge in some of the 

 Japanese specimens is covered with the polype-bearing bark, 

 the polypes near the base being smaller. " Chez ces derniers 

 (les exemplaires du Portugal) le corium polypigerum enveloppe 

 Paxis d^une maniere uniforme, il recouvre parfaitement Pune 

 des extremites de Paxis, la plus etroite, et de 1^ il s^etend 

 sans aucune interruption jusqu'aux f ou les |- de la longueur 

 totale. Les polypes places sur Pextremite de Paxis sont les 

 plus petits de tous" (Proc. Zool. Soc. 1865, p. 663, & 1864, 

 t. 22. f. 2). 



These observations seem to have been carefully made; and 

 they not only show that the living sunk in the sponge is not 

 universal in the genus, but they completely dispose of the theory 

 to which I shall have to refer, that what is called the axis of the 

 coral is in fact an integral part of the sponge, in which the 

 coral lives, and that what is called the bark is only a parasitic 

 Polythoa that accidentally grows on the elongated spicula of the 

 sponge. 



It would be very interesting to know how the Portuguese 

 species lives, and how it keeps itself erect in the sea, as in those 

 species also the polypes seem to be equally developed on every 

 side of the cylindrical coral ; and this could not be the case if it 

 did not live erect or nearly so. It cannot float like the cylin- 

 drical compound Medusae, as the axis renders the coral too 

 heavy for that purpose, and there is no inflated float to overcome 

 the specific gravity of the coral. 



It is to be hoped that Professor Bocage, who is still studying 

 the subject, will be able to explain this part of the history of the 

 animal. 



The Japanese, who collect these ''Glass Ropes'^ as ornaments, 

 are in the habit of inserting a bunch of them in the holes made 

 in the rock by the Pholades. A series of specimens so stuck 

 into a Pholas-iiole was exhibited by Mr. Huxley at the Linnean 

 Society last year. Professor Brandt has figured a similar group 

 (t. 2. f. 1). But it is quite a mistake to suppose that this is the 

 way in which the "Glass llope^^ lives in the sea. In the speci- 

 men which I examined, the cement could be seen by which they 

 were attached to the holes; and the specimens in the same 

 group varied from 2 inches to 16 inches in length, and they 

 all had the bark pushed down so as to be near the surface of 

 the hole. I saw one specimen placed in a hole, affixed with 

 the thick end of the spicula and the broadest end of the rope 

 downwards. 



In 1857, MM. Milne-Edwards and Haime, in the first volume 



