Coral between cups not blistered but ridged by extensions of 

 septa. (Plate 27) ^Montastrea cavernosa (Linnaeus) 



LARGE STAR CORAL 



47. Cups either separated, or if touching, walls not fused 



(Plates 24, 25) 48. 



Cups have common walls (Plates 6, 7, 13) 50. 



48. Cups usually close together, varying considerably in size and 

 shape, and walls well raised above surface. 



Javia (gravida Verrill 

 BRAZILIAN STAR CORAL 

 Cups usually 1 to 3 mm apart, more regular in shape and 

 walls only slightly raised (Plate 24, 26) 49. 



49. Surface of coral blistered in appearance. Septa do not ex- 

 tend between the cups. Cups often angular when crowded 

 (Plate 24) Solenastrea hyades (Dana) 



LOBED STAR CORAL 

 Surface of coral not blistered. Septa extend over space be- 

 tween cups (Plate 26) ?4ontastrea annularis (Ellis and 



Solander) 



COMMON STAR CORAL 



50. Septa protrude above surface, extending over common wall, 

 and relatively well separated. Edges of septa irregularly 

 hooked (Plate 1 3) 7avia fragum (Esper) 



STAR CORAL 

 Septa not so prominent, and are evenly crowded together 

 (Plates 6, 7) Septa beaded 51. 



51. Cups irregular in shape, 2 to 3 mm wide and up to 6 mm 

 long. 



Siderastrea stellata Verrill 

 STARLET CORAL 

 . Cups more regularly pentagonal, up to 5 mm wide (Plates 

 6, 7) 52. 



52. Cups 2.5 to 3.5 mm. Septa with inner margins almost per- 

 pendicular so that cavity is narrow and straight sided 

 (Plate 6) Siderastrea radians (Pallas) 



STARLET CORAL 

 Cups 3.5 to 5 mm. Septal margins sloping so that cavity is 

 more open (Plate 7) Siderastrea siderea (Ellis and 



Solander) 

 STARLET CORAL 



72 



