CHARACTERISTIC DEEP-SEA TYPES. — SEA-URCHINS. 98 
be capable of very rapid movements, if they at all correspond to 
those of their shallow-water allies. 
As it is brought to the surface Coelopleurus is most brilliantly 
colored, the test varying from a rich light chocolate in the inter- 
ambulacra to the brilliant orange or yellow ambulacral areas. 
Fig. 358. — Colopleurus floridanus. $. 
The primary radioles vary greatly in color, from a delicate straw, 
often nearly white, to a bright carmine or orange; the base of 
the spines being usually colored, and the shaft more or less ir- 
regularly banded. 
