OCEAN SURFACE DREDGINGS 45 



dark background in order to arouse the enthu- 

 siasm they deserve. 



To know something of their history and 

 nature we must consider some of the details 

 of structure of living representatives of these 

 homes or skeletons of creatures of long-past 

 ages. 



During the ' Challenger ' expedition vast 

 numbers of exquisite forms assumed by the 

 skeletons of the Eadiolaria were found in the 

 ocean surface dredgings. Some of them consist 

 only of spines radiating from the centre, which, 

 however, are often beautifully sculptured and 

 branched. In one particular form the number 

 of spines is always twenty, and these are all 

 arranged with absolute regularity at definite 

 angles to each other. All this mathematical 

 accuracy in a flinty framework about the 

 hundredth of an inch in diameter ! 



Some of the creatures appear as spiny balls, 

 one ball inside the other, and fitted together 

 by lattice works of flint of glassy texture. 

 Ball within ball, they remind one of the 

 Chinese carvings in ivory. 



