28 POPULAR HISTORY OF THE AQUARIUM. 



stars, diverging at an angle of 120 degrees ; the rays, straight 

 slender needles, perfectly cylindrical, except that they taper 

 to a fine point, smooth and transparent as if made of glass, 

 and highly refractive. 



" These spicula appear to me to be held together only by 

 their mutual entanglement and interlacing ; their points, in 

 the process of formation, have shot through and among each 

 other, so that it would be almost impossible to extract one 

 from any point without either breaking off its rays or tear- 

 ing away a considerable portion of its whole surface. The 

 rays shoot in the same plane, and in that plane the stars He, 

 not quite at random as to their direction, for tlie great ma- 

 jority have one point directed lengthwise from the mouth of 

 the tube towards the base. There are not wanting however 

 many which point in the opposite direction, and several at 

 intermediate angles. Of course it requires but little diver- 

 gence from the first-named direction to produce the second ; 

 still however the prevalent order appears to be this. 



" I cannot trace any fibrous or gelatinous matter in 

 which the spicula are set; but beneath the layer formed 

 by their interlacing points there is a surface composed of 

 round granules of transparent or pellucid matter, set as 

 close as possible, which are plainly seen between the cross- 



