from the N.W. Coast of Spain. 107 



greatly with the comparatively gigantic tubular forms of Lnf- 

 faria (whence the original designation of '"'' fistularis "), which, 

 as yet, have only been found in the seas between the two 

 Americas. 



I have stated that the network (figs. 3 & 8) subjacent to the 

 dermal sarcode in A. corneostellata " is composed of elongated 

 fusiform granuliferous cells aggregated together in a cord- 

 like form " (fig. 10, h) ] but this assertion, so far as the indi- 

 viduality of the cells is concerned, rests on the conjecture that 

 each elongated group of granules represents a distinct sponge- 

 cell. "Whether, however, the cord-like form is produced by 

 the mere contact of these cells, or they are thus united by an 

 intervening sarcode, I know of no means to determine. 

 Certain it is that, if they possess the same polymorphic power 

 as the soft parts of the sponge generally, this network must 

 aiFord considerable support to the whole structure, and thus 

 also yield to that of the dermal sarcode about it, whose poly- 

 morphic power we know to be such in Spongilla that it can 

 extemporize and close pores in its substance wherever and 

 whenever requisite. 



The ova, so far as my examination extended (and I examined 

 many) , did not appear to have gone beyond cell-multiplication ; 

 that is to say, none presented rudiments of the horny structure 

 like unto the development of spicules in the ova of the spicu- 

 liferous sponges at this period. What the colourless albu- 

 minoid concretions may be which I have not figured I am not 

 able even to conjecture. 



The spongozoa presented nothing further than the passive 

 form above described. 



Sudden death, by immersion in a preservative fluid during 

 active life, would seem more calculated to cause many poly- 

 morphic parts of the sponge to retain their active forms than 

 gradual death. At the same time it cannot be ignored that 

 the pores in the dermal sarcode, which is as polymorphic as 

 any other part of the sponge, do appear to be retained under 

 any circumstances, as if, instead of being merely extempo- 

 raneous, they had been established holes endowed with a 

 sphinctral power of contraction or dilatation as required. 



As regards increase of the horny element of the skeleton 

 during the general groioth of the sponge, a cell was often 

 observed to be fixed to the side of a ray of one of the stellates 

 by a transparent film of a horny nature, apparently extended 

 over it from the surface of the ray itself (fig. 4, e ; 5, c). In 

 some instances this cell was observed to have undergone in- 

 crease in size, elongation, and the addition of concentric horny 

 layers to its circumference (fig. 5, d) ; while in others it was 



