of confusion is due to the considerable variation which 

 may take place in corals as a result of the changing 

 nature of their surroundings. In these cases a whole 

 series of similar forms should be examined before a defi- 

 nite conclusion is reached. Only rarely, however, should 

 it be necessary to use the more technical literature. This 

 is nevertheless listed in the bibliography. 



Use of the key is simple. Starting at 1, there is a 

 choice of two descriptions. The description which more 

 closely fits the specimen is selected. Opposite the selected 

 description is a number which refers to another pair of 

 descriptions further on in the key. By determining the 

 appropriate one of these and continuing the process the 

 reader will eventually arrive at the name of his specimen. 

 In order to provide a quick check on the accuracy of 

 identification references to photographic illustrations 

 are placed throughout the key. 



SIMPLIFIED KEY TO THE REEF CORALS OF THE 

 WESTERN ATLANTIC 



1 . Coral has smooth surface covered with fine pinholes. No cups. 



TdiWepora akicornis Linnaeus 

 STINGING CORAL 

 Coral surface honeycomb patterned or broken by cups or 

 grooves 2. 



2. Coral never forms branched or massive structure, but consists 

 of single cups. 



Astrangia soUiaria (Lesueur) 

 DWARF CUP CORAL 

 Cup always united to form a branched massive or encrusting 

 structure 3. 



3. Coral is branched (Plates 2, 3, 8, 22, 28, 35, 41) 4. 



Coral is not branched 15. 



4. Cups less than 10 mm in diameter 5. 



Cups over 1 5 mm in diameter and arranged singly at end of 

 short branches (Plates 35, 41) „ 13. 



5. Cups flush with the coral surface, forming a honeycomb pat- 



65 



