ISOPHYLLIA. 71 



15 in a centimeter. The ridges are sometimes slightly flattened on top 

 and marked generally with a narrow but distinct furrow. Columella 

 w^ell developed, papillose. 



Though not sure of the identification, as indeed will be mostly the 

 case in any attempt to identify the numerous species of Symphyllia too 

 imperfectly characterized by Duchassaing and Michelotti, I prefer not 

 to introduce a new name, as there are, no doubt, many superfluous ones 

 in the number. 



The Museum of Comparative Zoology has a sjiecimen from Florida 

 and one from Bermuda. 



Isophyllia dipsacea Ag. Ms. 



Sj/mph/llia f dipftacea Edw & H. 



Mussa dipsacea Dana. 



Non SijmphijUia guadulpensis Edw. & H. 



Rather common, quite a number of fine specimens in the Museum of 

 ComjDarative Zoology. 



Isophyllia guadulpensis Poijrt. 



SympliyUia guadulpensis M.-Edw. & H. 

 Isophyllia rigida Vehrill. 

 Non Astrcea rigida Dana. 



The specimens labelled by Mr. Yerrill all agree in having lamellar 

 costa3 when young, much more marked than in any other species. The 

 other characters are rather vague. 



The diagram of the calicles of Astrcea rigida given by Dana showing a 

 hexao-onal limitation of the calicles, so different from the irreorular, 

 partly meandriform shape of those of the species in question, seems to 

 preclude the identification as made by Verrill. The imperfect descrip- 

 tion seems to call for a new. one. Corallum flat-hemispherical ; epitheca 

 rudimentax}^ or none ; cost^e sul^lammellar, particularly in the joung, 

 spinulous ; calicles rarely simple, mostly in sinuous series with two or 

 three centres. Ridges rounded, with very small furrow on top. Septa 

 closel}^ set, rather equal, 10 to 12 to a centimeter, sparselj^ granuhir 

 on their faces, with rather strong triangular teeth ; columella papillose. 



The young divide quite regularly into six lobes, corresponding to 

 the systems, the primary septa enlarging and forming the partitions 

 between the lobes. 



