86 Dr. S. Loven on a remarkahle Sponge 



called the head answers to " the sponge " of the Hyalo- 

 nema, and the stump of the stem to the splendid ^^ twisted 

 cord " hitherto supposed to rise from the sponge. But the 

 difference of size is very considerable. The large specimen of 

 Hyalonema figured by Professor Max Schultze has ^^ the 

 sponge " ten times as high and in volume more than six 

 hundred times as large as the head of our sponge, " the twisted 

 cord " eight times as long and very much thicker. 



The opinions as to the true nature of the Hyalonema have 

 been widely different among naturalists. That the zoophyte 

 Palythoa and the sponge Hyalonema are two separate organisms 

 no doubt is possible. Professor Max Schultze's researches 

 have settled this question, on which opinions have been so 

 divided. In another point all who have treated of the Hya- 

 lonema as a natural production have agreed : they all assume 

 " the sponge " to be the basal part, " the coil " a part arising 

 from it. 



But if we regard the Hyalonema in the contrary manner, if 

 we place it so that ^' the sponge " is upwards, ''the coil" down- 

 wards, and suppose this to be only a part of the stem, torn off 

 by the fisherman's line, the remainder having been left at- 

 tached to the bottom (in the same manner, for example, as the 

 deeply immersed Lygus mirahilis (O. F. M.) is so often cut off 

 by the dredge) , and if we then compare it more closely with the 

 sponge here described and figured, we shall have, as I will try 

 to show, a view of its structure and habits approaching more 

 nearly to the truth than that now generally accepted. 



The surface of the Hyalonema called the lower one of " the 

 sponge " is now the upper one, corresponding to that which is 

 marked a in fig. 1, and shown by fig. 2. In our sponge this 

 surface is provided with a great osculum, in the bottom of 

 which the canal-system is seen entering the inner parts of the 

 head. Professor Max Schultze is the only author who has 

 described the same surface in the Hyalonema. If ever at- 

 tached to the bottom, it ought to bear traces of it ; sand, frag- 

 ments of shells, Foraminifera would, as usual (for example, 

 in Euplectella cucumer^ Owen, and E. o^pergillum^ Owen), 

 adhere to it. This, however, is not mentioned. On the otlier 

 hand, there open on this surface '' not less than six irregularly 

 oval apertures, half an inch wide, which are in connexion with 

 anastomosing canals, bordered by a membranous and porous 

 network of siliceous needles. These canals can be followed as 

 far as two inches deep in the sponge, and form an irregular 

 lacunar system, which is in conjunction, through the fine 

 meshes of the spongious network, with the openings on the 

 surface." It is evidently the oscula oi Hyalonema^ v^'iih Xh.^ 



