CHARACTERISTIC DEEP-SEA TYPES. — CORALS. 



L55 



Rugosa is only apparent, there being originally six primary 

 septa, two of the systems remaining gen- 

 erally undeveloped. 'Hie [>olyp of 

 Haplophyllia paradoxa is scarier, with 

 about sixteen rather long tentacles. In 

 another species, Duncania barbadensis, 

 the polyp is deep flesh-colored, and 

 there are from 25 to 30 conical tenta- 

 cles with inflated tips. 



The AntipathidaB constitute a very 

 natural and homogeneous group, hav- 

 ing the property of secreting a horny polypidom. One of the 

 most common West Indian species is Antipathes spiralis; it 



• 481. — Haplophyllia para- 

 doxa. 2, (Pourtales. ) 



§1 



Fig. 482. —Antipathes spiralis. \''. 

 (Pourtales. ) 



Fig. 483. — Antipathes colnmnaris. ^. 



(Pourtales.) 



has been dredged from no less than twenty-three stations, in 

 depths ranging from 45 to nearly 900 fathoms. The polyps of 



