ISOPHYXLIA. 71 



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

 and marked generally with a narrow but distinct furrow. Columella 

 well developed, jjapillose. 



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 specimen from Florida 

 and one from Bermuda. 



Isophyllia dipsacea Ac Ms. 



Symphyllia ? dipsacea Edw & II. 



Mussa dipsaa u Dana. 



Nod Symphyllia guadulpt nsis Edw. & II. 



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

 Comparative Zoology. 



Isophyllia guadulpensis Pofrt. 



Symphyllia guadulpensis M.-Edw. & H. 

 Isophyllia rigida Verrill. 

 Xon Astrasa rigida Dana. 



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

 costse when voung, 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 

 hexagonal limitation of the calicles. so different from the irregular, 

 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 

 rudimentary or none; costa> sublammellar, particularly in the young, 

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

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

 closely set. rather equal, 10 to 12 to a centimeter, sparsely granular 

 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. 



