444 BULLETIN 103, UlSTITED STATES NATIONAL MUSEUM. 



1846. Pavonia siderea Dana, U. S. Expl. Exped. Zooph., p. 331. 



1850. Siderastrea siderea Milne Edwards and Haime, Ann. Sci. nat., ser. 3, 



Zool., vol. 12, p. 141. 

 1857. Astraea siderea Milne Edwards and Haime, Hist. nat. Corall., vol. 2, 



p. 509, pi. D7, fig. 2. 

 1863. Siderastraea grandis Duncan, Geol. Soc. London Quart. Journ., vol. 19, 



p. 441, pi. 16, figs. 5a, 56. 

 1871. Siderastraea siderea Pourtales, Mus. Comp. Zool. 111. Cat. No. 4, p. 81. 

 1895. Astraea siderea Gregory, Geol. Soc. London Quart. Journ., vol. 51, p. 278. 

 1901. Siderastrea siderea Vaughan, Geolog. Reichs-Mus. Leiden Saniml., ser. 2, 



vol. 2, p. 62. 



1901. Siderastrea siderea Vaughan, U. S. Fish. Com. Bull, for 1900, vol. 2, p. 309, 



pi. 14, figs. 1, 2; pi. 16, fig. 1. 



1902. Siderastraea siderea Verrill, Conn. Acad. Arts and Sci. Trans., vol. 11, 



p. 151, pi. 30, figs. 2, 3. 



1903. Siderastraea siderea Duerden, Nat. Acad. Sci. Mem., vol. 8, p. 588, pis. 



22-24, figs. 150-160. 



1915. Siderastrea siderea Vaughan, Washington Acad. Sci. Journ., vol. 5, p. 597. 



1916. Siderastrea siderea Vaughan, Carnegie Inst. Washington Yearbook No. 14, 



p. 228. 



This species forms much larger masses than S. radians, the other 

 abundant living species of Siderastrea in the West Indies and Florida, 

 and is a common exposed-reef coral. The calices average larger than 

 in S. radians, usually 4 to 5 mm. in diameter, occasionally smaller, 

 3 to 3.5 mm. in diameter. The intercorallite walls are more acute 

 and the septal margins are more sloping; but, as is shown on plate 

 114, figure 3, on some areas the corallite wall may occur in a slight 

 depression (pi. 114, fig. 2). The septa are normally in four complete 

 cycles, arranged as in figure 3, on plate 114. The tertiary septa fuse 

 to the secondaries, and the quaternaries to the tertiaries nearer the 

 wall than in S. silecensis, the next species to be described. The 

 septal margins are more finely dentate than in S. radians, and usually 

 the columella is distinctly, finely papillate. 



The foregoing notes are on shallow-water specimens, and apply to 

 specimens ranging in locahty from Barbados to the Bahamas in the 

 West Indies, from Central America, and from Florida. About one- 

 half mile south of Loggerhead buoy, Tortugas, in water between 8 

 and 9 fathoms, I dredged three specimens of S. siderea that show very 

 interesting variation. The size and shape of the calices, the character 

 of the wall, the number of septa, and the axial fossae are as usual 

 in the species; but the septa are thicker, the septal pectinations are 

 more conspicuous, and the columellar papillae are solidly fused or 

 there is a single, stout, compressed axial tubercle. A group of calices 

 is shown on plate 122, figure 1. These specimens agree in all essen- 

 tial particulars with a specimen from the Bowden marl of Jamaica, a 

 description of which follows: 



Description of specimen froTn Bowden, Jamaica (pi. 122, figs. 3, 3ft). — • 

 CoraUum with a rounded upper surface and a flattish base: epithe- 



