86 Dr. 8. Lovén on a remarkable 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 mirabilis (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 Huplectella cucumer, Owen, and E. aspergillum, Owen), 
adhere to it. This, however, is not mentioned. On the other 
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 of Hyalonema, with the 
