FAMILIES AND GEI^EEA OF THE MADEEPOEAEIA. 91 



producing ridges at tlie calicular surface ; these are simple, 

 and are arranged in a radiating manner, and commence and end 

 at the centres of star-like areas. The series are narrow, and 

 the calicinal centres are almost completely indistinct. Columella 

 absent or rudimentary. 

 Distrihution, — Fossil. Cretaceous : Europe and England. 



III. Alliance SYMPHYLLIOIDA. 

 Fissiparous Astrseidse, with coralUtes in linear series with distinct caU- 

 cinal centres. Walls united directly or by costse, or only free to a certain 

 extent. Septa dentate or spined or entire. 



Tribe I. With dentated septa. 

 Tribe II. With entire septa. 



I. Genus Symphyllia, Ed. & H. 

 Genus Phyllogyra, Tomes. 

 Genus DiMORPHOPHYLLiA, Rcuss. 

 Genus Stibastr^a, Etallon. 

 Genus Latiphyllia, E. de From. 

 Genus Mycetophyllia, Ed. & H. 

 Genus Ulophyllia, Ed. & H. 

 Genus Tridacophyllia, Blainville. 

 Genus Colpophyllia, Ed. & H. 

 Genus Scapophyllia, Ed. & H. 



II. Genus Plerogyra, Ed. & H. 

 Genus Physogyra^ Quelch. 

 Genus Phytogyra, d'Orb. 



The genera Isophyllia, Ed. & H., and Gyrosmilia, Ed. & H., are 

 absorbed. 



Tribe I. 



Genus Symphyllia, Milne-JEdwards Sf Jules Haime, Hist. Nat. 

 des Corall. vol. ii. p. 369 (1857). 

 Syn. Isophyllia, Ed. & H. 



The colony is massive, convex above or snbplane. The corallites 

 are in short or long linear series, which are united by their walls 

 completely, or having a slight groove between them, or united 

 below by the walls and close to the surface by costaD and exotheca. 

 Calicular centres distinct in the series. Columella spongy. Septa 

 numerous, much spined. Collines stout, tall, may be furrowed 

 on the top. Endotheca abundant. 



The genus is divided into grouj)s of species characterized by the 

 amount of mural fusion. In one group the walls are so united 

 that no groove is seen on the " collines " between the corallites. 

 In the second there is a narrow groove there ; and in the third 



