180 JULY. 



five principal sets or bands, with blank intervals be- 

 tween, about twice as wide as the drilled bands. Then 

 each band comprises two series, each of which contains 

 a double row of orifices. These last, again, do not con- 

 stitute a single unbroken line, but an interrupted or 

 zig-zag line, which is, in fact, made up of a number of 

 short diagonal rows ; three holes in each diagonal, set 

 one after another. 



Put the living and the dead together. These tiny 

 orifices, as minute as the point of the finest cambric- 

 needle could make in a bit of paper, afford exit to the 

 suckers, which are, of course, equally numerous. Through 

 these pass the slender pellucid tubes, filled with elastic 

 fluid, which carry at their tips a flat ring of calcareous 

 shell, affording to each the form and firmness to make 

 each one an adhesive sucking disk, in the centre of 

 which a tiny vacuum is created at will by muscular 

 retraction. 



But this is not all Again, look at the living Sea- 

 Urchin. It bristles with the rosy-tipped spines, which 

 have a satiny lustre, owing to the reflection of the light 

 from the delicate ridges and furrows with which the 

 whole is fluted, like an Ionic column in miniature. 

 How they are all moving, and swaying to and fro on 

 their bases, quite independently of each other, how- 

 ever, making circles and traverses in the water with 



