194 PROCEEDINGS OF THE JSTATIONAL MUSEUM. vol.xxii. 



Genus SEPTASTR^^A d'Orbigny (1849), emend. Hinde. 



SEPTASTR^A SEXRADIATA (Lonsdale). 



1837. Astrea sp. W. B. and H. D. Eogers, Trans. Am. Phila. Soc, new ser., V, p. 338. 

 1845. Colmnnaria f serrarfm/a Lonsdale, Quart. Jour. Geol. Soc, I, p. 497, figs, a, b. 



1845. Columnaria f sexradiata Lvell, Quart. Jour. Geol. Soc, I, p. 416. 



1846. Astroitis sexradiata Dana, Am. Jour. Sci., 2d ser., I, p. 221. 



1846. Astroitis sexradiata Dana, U. S. Exploring Expedition, Zoophytes, p. 722. 



1848. Columnaria ? sexradiata Bronn, Index PaLeontologicus, I, p. 321. 



1849. Septastrcea forbesi Edwards and Haime, Ann. des Sci. Nat., 3d ser., XII, p. 64. 

 1849. Septastrma subramosa d'Orbigny (nominal), Note sur les Polyp, foss., p. 9. 

 1852. Septastrcea subramosa d'Orbigny, Prodr. de Pal., Ill, p. 146. 



1857. Septastrma forbesi Edwards and Haime, Hist. Nat. des Corall., II, p. 450. 

 1857. Astrangia f belJa Edwards and Haime, Hist. Nat. des Corall., II, p. 615. 

 1861. Astrangia ? bella de Fromentel, Introduction Polyp, foss., j). 237. 

 1861. Septastrma forbesi de Fromentel, Introduction Polyp, foss., p. 174. 

 1851. Septastrcea forbesi Edwards and Haime, Archiv. Mas. Nat. Hist., V, p. 115. 

 1864. Septastrwa ? sexradiata M^KVAi., Clieck-Hst Invert. Foss., N. Am. Miocene, p. 1. 

 1864. Septastrcea forbesi Meek, Check-list Invert Foss. N. Am. Miocene, p. 1. 

 1884. Astrea ep. W. B. and H. D. Rogers, Reprint of Ann. Reports and other Papers 

 on Geology of the Virginias, p. 667. 



1886. Glypliastrwa forbesi Duncan, Abstract. Proc. Geol. Soc. London, No. 495, p. 18. 



1887. Glypliastrcea sexradiata Duncan, Quart. Jour. Geol. Soc, XLIII, p. 30. 



1887. Ghjphasircea forbesi Duncan, Quart. Jour. Geol. Soc, XLIII, p. 29, pi. in. 



1888. Septastrcea sexradiata Hinde, Quart. Jour. Geol. Soc, XLIV, p. 219, pi. ix, 



figs. 6-16. 

 1888. Septastrcea forbesi Hinde, Quart. Jour. Geol. Soc, XLIV, p. 218, pi. ix, figs. 



1-5, 7-15, 17. 

 1895. Septastrcea sexradiata Gane, Johns Hopkins Univ. C ire, XV, No. 121, p. 10. 



Oolouy incrusting at base, rising into cylindrical compressed stems 

 with short, rounded branches or of large flattened masses with lobate 

 and digitiform expansions. Corallites with walls iu close contact but 

 distinct one from another, subcylindrical iu the interior, although pris- 

 matic at the surface of the corallum. The matured calices are shallow 

 with thickened margins, an impressed line generally marking the 

 division between the individuals; the floors of the calices, which have a 

 dome-shaped elevation in the center, are entirely closed with stereo- 

 plasm, the upper edges of the septa alone slightly projecting. When 

 the calices are immature or much crowded the walls are thin and the 

 floor near its periphery is incomplete. The entire calice when per- 

 fectly preserved is covered with minute tubercles, although the surface 

 of the septa in the interior of the corallites is smooth. Septa usually 

 12 in the lower portion of the corallite; in the calice a rudimentary 

 third cycle is often added. Abnormally the calice may possess from 

 to 36 septa. The inner septal ends are often intertwisted to form a 

 pseudocolumella. Dissepiments very thin, irregularly developed, fre- 

 quently at the same level in the different interseptal loculi, usually 

 from 1 to 2 mm. apart, the uppermost dissepiment of the corallite form- 

 ing the base to the infilling stereoplasm. Increase by gemmation from 

 buds formed at the interspaces between the walls of adja'eiit mature 

 corallites. 



