TAXONOMIC KEY TO GENERA OF LIVING WESTERN 

 ATLANTIC CORALS. (After Vaughan & Wells) 

 (Descriptions leading to ahermatypic corals in brackets.) 



1 Septa laminar or rudimentary consisting of relatively few 



simple (rarely compound) trabeculae strongly inclined 

 from axis of divergence (Suborder ASTROCOENIIDA) 2 

 Septa laminar or fenestrate, well developed, consisting of 

 numerous simple or compound trabeculae slightly in- 

 clined from the axis of divergence 5 



2 Peritheca almost invariably absent. Septal margins 



beaded. (Family ASTROCOENIIDAE) 3 



Peritheca extensively developed 4 



3 Septal margins with well marked dentations. Corrallum 



cerioid Astrocoenia 



Septal margins smooth or minutely dentate. Corallum 

 plocoid Stephanocoenia 



4 Peritheca nonporous, solid, or vesicular (Family 



Seriatoporidae) Tdadracis 



Peritheca porous, ventriculate (Family Acroporidae) 



Acropora 



5 Septa consist of one or more fan systems of simple or 



compound trabeculae, porous or solid, margins beaded 



or dentate 6 



Septa consist of one fan system of mostly simple trabe- 

 culae. Margins mostly smooth 29 



6 Septa fenestrate composed of simple trabeculae, but often 



appearing laminar in later stages, more or less porous, 

 margins beaded; simple synapticulae present. (Sub- 

 order FUNGIIDA) 7 



Septa laminar, nonporous, margins dentate, sometimes 

 minutely; synapticulae absent. (Sub-order FAVIIDA) 9 



7 Septa fenestrate in young stages and higher cycles, 



laminar in later stages (Super family Agariciodae — . 8 

 Septa fenestrate and porous in all stages (Family 



Poritidae) Pontes 



8 Wall septothecal in ephebic stage, sometimes reduced or 



absent. Septa of simple trabeculae, laminar. (Family 



Agariciidae) Agaricia 



Wall synapticulothecal. Fenestrate structure marked (less 

 so in later stages) . Septa of simple and compound tra- 

 beculae, more or less porous. (Family Siderastreidae) 



Siderastrea 



i04 



