128 Mr. J. E. Gray's Outline of an Arrangement of Stony Corals, 



a. Coral cell circumscribed, with only a single centre ; lamince 

 smooth or very slightly serrated; animal gemmiferous. Ocellina, 

 Ehr. 



Dendrophyllidje. 



Coral moderately hard, porous ; surface minutely longitudi- 

 nally striated ; cells truncated, concave, generally with a convex 

 centre. 



Tubastrea, Dendrophyllia, Bl. (Cladocora, Ehr,) Explanaria, 

 Lam. (Gemmipora, BL) 



OcULINIDiE. 



Coral hard, covered with an enamel surface ; cells concave, with 

 radia extended over the edges, or with the outer edge radiately 

 grooved. 



Cyathina, Ehr. Oculina, Lam. Anthophyllum, Schw. (A, 

 fasciculatum.) 



b. Coral cells circumscribed or not defined j confluent, with many 

 centres ; lamina serrated and extended, reflexed over the outer sur- 

 face of the coral, or extended from centre to centre ; coral hard, 

 with a hard enamel surface ; animal growing by spontaneous divi- 

 sion. Dsedalina, Ehr. 



Caryophylliad^. 



Cells deep, round (or sinuous with many centres) ; laminse torn, 

 serrated, with a sinuous twisted centre, and often with interme- 

 diate smaller plates not reaching the centre ; animal continuing 

 to grow upwards and gradually to expand in diameter. 



Caryophyllia, Lam. (Lobophyllia, Bl.) Tridacophyllia, BL 

 Manicina, Ehr. Dipastrea, BL 



MEANDRINIDiE. 



Cells deep, elongate, compressed, with a single series of equal 

 laminse forming a single linear impressed line in the centre ; ani- 

 mal continuing to grow upwards and gradually to expand in 

 diameter. 



? Fungia, Lam. Flabellum, Lesson. Meandi'ina, Lam. Mon- 

 ticularia, Lam. 



Agariciad^e. 



Cells shallow, not circumscribed, but scattered and united to 

 one another by laminse on the star-bearing surface of the coral ; 

 animal expanding out laterally, forming a leaf-like frondose coral. 



***Agaricia and Pavonia, Lam. Stephanocbra, Ehr. Echi- 

 nastrea, Blainv. ? x\strsea, Lam. 



