146 



THREE CRUISES OF THE " BLAKE. 



into joints alternately long and short ; the longer ones white, 

 hollow, and calcareous, and the shorter ones horny brown. 

 We should also mention Primnoa Pourtalesii (Fig. 458), a 

 plumose gorgonian with regularly pinnate branchlets all in one 

 plane. To this genus belongs also the huge bush coral Primnoa, 



Fig. 458. Primnoa Pourtalesii. |. (Verrill.) 



which grows to the height of man, and has an axis as thick as 

 a man's leg. 



Many of the gorgonians are beautifully phosphorescent when 

 brought to the surface, and their closely clustered branches, as 

 in Calyptrophora (Fig. 459) are the abode of hosts of Crustacea, 

 annelids, - mollusks, and echinoderms, which find shelter there 

 from their enemies. 



The Actinidae, or sea-anemones, so common in shallow water, 

 are represented by a number of species in our deep waters ; 

 many of them are finely colored, some of them developing a 

 peculiar base adapted to soft bottoms, representing perhaps, as 

 has been suggested by Verrill, a primitive type from which the 



