372 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



The usual number of septa is three complete cycles; primaries and 

 secondaries subequal, reach the columella; tertiaries short, inner 

 edges free. The septa present only one noteworthy difference from 

 what is usual in 0. annularis; that is, the margins of the primaries 

 and secondaries are less exsert. 



Columella not very large, loose, trabecular. 



The three salient characteristics of this variant are (1), its growth 

 form; (2), the tilted calices; (3), the lower (less exsert) margins of 

 the primary and secondary septa. 



Geologic horizon. — Pleistocene. 



NOTES ON SYNONYMY. 



A number of other names need to be considered in greater or less 

 detail. 



Gregory 1 applied the name Orbicella acropora (Linnaeus) to this 

 species. He accepted the determination of the species by Milne 

 Edwards and Haime, 2 who separated it from 0. annularis by its 

 having no septa corresponding to the last cycle of costae. Gregory 

 showed that occasionally in typical specimens of 0. annularis the 

 last cycle of septa may be absent while the costae are present, thus 

 breaking down the character used by Milne Edwards and Haime to 

 distinguish the sj>ecies. I accepted Gregory's conclusion, and 

 followed him in my paper on Some fossil corals from the elevated 

 reefs of Curacao, Arube, and Bonaire, and subsequent papers. 

 Professor Verrill, in his Variations and Nomenclature of Bermudian, 

 West Indian, and Brazilian reef corals, 3 declares that Madrepora 

 acropora Linnaeus a is utterly indeterminable," and takes the next 

 later specific name, annularis Ellis and Solander, for the species. 

 Subsequent study convinced me that Professor Verrill is right, and 

 I published my change of opinion in a paper on Some recent Changes 

 in the Nomenclature of West Indian corals. 4 Therefore, I now 

 believe that Madrepora acropora Linnaeus should be considered as 

 undeterminable and that the name should be dropped from coral 

 nomenclature. 



The type-specimen of Madrepora faveolata Ellis and Solander is 

 preserved in the Hunterian Museum of the University of Glasgow, 

 where I have seen it, and Prof. Graham Kerr has kindly sent me a 

 photograph. It is a worn specimen, considerably infiltrated with 

 calcium carbonate, and is probably the same as Orbicella annularis. 



Astraea {Orbicella) stellulata Dana has been carefully redescribed by 

 Professor Verrill from Dana's types, which are preserved in the Yale 

 University Museum. The following is his description: 



They 5 are beach-worn specimens of a true Orbicella, more or less infiltrated with 

 calcium carbonate, to which the unusual solidity of the walls and exothca, in some 



i Geol. Soc. London Quart. Journ., vol. 51, p. 272, 1895. 



2 Hist. nat. Corall., vol. 2, p. 477 1857. 



s Conn. Acad. Arts and Sci. Trans., vol. 11, p. 94, 1902. 



* Bid. Soc. Washington Proa, vol. 15, p. 56, 1902. 



6 Conn. Acad. Arts and Sci. Trans., vol. 11, p. 96, pi. 15 ,flg. 2, 1902. 



