THE LIVING WORLD. 
37 
renders it a beautiful creature. It is, however, dangerous to handle, sihce its 
sharp spines both sting and benumb. 
The Marsupial Sea-Urchin (Hemiaster Philippii) is remarkable foi 
having four deep cavities, in which, like the opossum, it receives its young. 
medusa head (Astra caput medusa;). burdock holothuria. 
(Synapta inharcus.) 
PURPLE HEART URCHIN. 
{Spatangus purpureus.) 
Snake Star, or Pluteus, is the name given to the embryonic sea-urchin, and 
is of great interest because so unlike the Echinoderm, into which it is to be meta¬ 
morphosed. It has a bilateral (two-sided), symmetrical (side corresponding to 
side), non-radiated body, which is mostly obscured by an apparently helpless 
tangle of eight long arms, supported by slight calcareous rods. As these arms 
sun star>fish (Solaster papposus ) AND young. young hair stars. 
(Comatula jnediterranea.) 
vibrate they suggest some of the most grotesque and horrible drawings of 
Gustave Dore. The creature swims by a parachute-like opening and closing 
of its arms. 
The Brittle Star-fish is constantly engaged in breaking itself into pieces, 
but it repairs the damage as speedily as it occasions it. 
