CONTINENTAL SHELF 237 



Pennatulida (Fig. 168), the sea-fans, or Gorgoniacea 

 (Figs. 169, 170), the fleshy masses of the " dead-men's- 

 fingers " (Alcyonaria), the sea anemones, the red or 

 precious coral (Corallium), and the true corals (Madre- 



FIG. 166. LEPTOPENUS, A DEEP-SEA CORAL (" CHALLENGER "). 



poiaria), both colonial (Fig. 26, p. 90) and solitary 

 (Fig. 166) ; the true corals are by no means confined 

 to the warmer seas, although it is only there that they 

 display their full luxuriance. 

 Starfishes (Fig. 174), brittle-stars (Fig. 173), sea- 



