56 CCELENTERATA AND 



1. Sclerobase with nodes and internodes. 



2. Sclerobase horny. 



Paragorgia. 

 Anthothela. 

 Acanella. 



Acanthogorgia. 



Paramurieea. 



Primnoa. 



B. 1. 

 Paragorgia. Coral large, branching with axis formed 

 of spicules. No horny deposit. 



P. arborea. 



Anthothela. Coral irregular with spiculose axis of fus- 

 iform spicules. Calycles prominent, not retractile". Ccen- 

 osarc thin. Spicules warty in ccenosarc and calycles. 



A. insignis. 



Acanella. Branched with nodes larger than internodes. 

 Nodes very hard. Ccenosarc thin. Tentacles still' with 

 spicules. 



A. Normani. 



B. 2. 



Acanthogorgia. Coral slender, flexible, branched, 

 bushy. Ccenosarc thin with small, curved, wart-like spi- 

 cules which do not project. Calycles elongated. Disk 

 surmounted by eight groups of long, divergent, spine-like 

 spicules. Body spicula, rarely projecting. 



A. armata. 



Paramurieea. Differs from Acanthogorgia in possess- 

 ing shorter calycles and shorter marginal spines. Spic- 

 ules irregular, flat, branched. 



P. boreal is. 



