84 On the " Glass-Rope " Hyalonema. 



perfect and imperfect specimens of Hyalonema, in the Museum 

 of Leyden, and in ] 860, published an elaborate description of 

 its structure. I can entertain no doubt of the soundness of 

 Professor Schultze's conclusions. The present sketch has 

 been chiefly abstracted from his memoir, though I may add that 

 I have lately had an opportunity of verifying his observations 

 in almost every detail. The conical sponge, which forms the 

 base of the fabric, I believe to be the body-mass of Hyalonema 

 Sieboldi, a sponge allied to the genus Alcyoncellum, Quoi and 

 Gaimard (Euplectella, Owen) ; and the silicious coil to be an 

 appendage of the sponge, formed of modified spicules, and 

 recalling in some respects the fringe of long calcareous styles 

 surrounding the osculum in our common little Sycon ciliatum. 

 The zoophyte is of course a distinct animal altogether, whose 

 only connection with the sponge is that it is apparently almost 

 constantly parasitical upon it. This style of association is not 

 at all uncommon ; take for example Pagurus Prideanxii and 

 its attendant Adamsia, and especially Palythoa axinellai 

 (Schmidt), a constant parasite upon Axinella cinnamomea, and 

 A. verrucosa, two Adriatic sponges. 



On looking over Dr. Bowerbank's papers on sponges in the 

 Philosophical Transactions, I at first took for granted that he 

 adopted the views of Valenciennes and Schultze. In an 

 answer which he published in the Annals and Magazine of 

 Natural History for November last to Dr. Gray's paper, he, 

 however, distinctly states that he has " always maintained that 

 the silicious axis, its envelopment, and the basal sponge were 

 all parts of the same animal." The polyps he regards as 

 " oscula," forming with the coil a " columnar cloaca! system." 

 This view, I confess, I do not fully understand. At all events, 

 Dr. Bowerbank thinks that the so-called ' ' polypigerous crust" 

 is a part of a sponge. That this position seems to me to be 

 utterly untenable, my description of the Palythoa will suffi- 

 ciently show. 



In 1864, Senhor J. V. Barboza de Bocage, director of the 

 Museum of Natural History of Lisbon, communicated to the 

 Zoological Society of London the interesting intelligence that 

 a species of Hyalonema had been discovered on the coast, of 

 Portugal, and in 1865 he published, in the proceedings of the 

 same society, an additional note " on the habitat of Hyalonema 

 Lusitanicum. }> It appears that the fishermen of Setubal, on 

 the Portuguese coast, frequently bring up on their lines, from 

 a considerable depth, coils of silicious threads, closely resem- 

 bling those of the Japanese species, which they even surpass 

 in size, sometimes attaining a length >of about two feet. The 

 fishermen seem to be very familiar with them. They call them 

 " sea-whips," but, with the characteristic superstition of their 



