238 THE CROWNED SPONGE. 



GRANTIA CILIATA. 



On the same Alga I find a compound specimen of 

 another pretty and interesting sponge of the same 

 genus, Grantia ciliata. It is seated near the edge 

 of the frond of the sea-weed, and sends up two little 

 oval lobes with short necks, of which a very exact 

 notion may be obtained by comparing them with the 

 bottles in which soda-water is sold ; but they are not 

 more than -J inch in height. The oval body is bristled 

 over with slender simple spiculse, all pointed, some 

 abruptly, others very gradually : they vary much in 

 thickness and length, some being of excessive tenu- 

 ity; they stand out in all directions from the sur- 

 face, like the quills of a porcupine, but there is a 

 slight tendency to point forward. Abundance of loose 

 granulous or floccose matter is entangled among the 

 spines, but this is probably accidental and uncon- 

 nected with the organization of the sponge. The 

 colour is dead-white ; and this I should suppose to 

 be produced by the reflection of light from the thou- 

 sands of shining spiculse, just as the whiteness of 

 snow is merely the light reflected from a vast number 

 of minute crystals of ice. 



The neck of this bottle-like sponge consists of a 

 dense fringe of the ordinary spiculse, perhaps more 

 slender than the average, which are set around the 

 orifice like a crown, pointing forwards and a little 

 outwards; so as to perfect the resemblance to a 

 bottle-neck. 



I incline to think that the stream of water periodi- 



