146 EOCENE AND LOWER OLIGOCENE CORAL FAUNAS. 



outer surface of the coeiienchyma is minutely granulate. The axial portions 

 of the branches are spongy. In the axial portion tlie corallites are joined 

 to one another directly by their walls or costae, or are separated by exotheca. 

 As the colony grows older, the corallites bend outward, so that ultimately 

 their axes are nearly at right angles to the external surface. Septa in three 

 cycles; those of the first and second cycles reach the columella; margins 

 entire; surfaces smooth; inner ends of those of the first and second cycles 

 somewhat thickened. From the sides of the septa wing-like processes are 

 developed, which extend across the interseptal loculi and fuse, thus forming 

 the endotheca. Tlie dissepiments' are often inclined; are very abundant. 

 No pali. Columella well developed, false, formed by the fusion of the 

 internal margins of the septa of the first and second cycles. Its upper sur- 

 face is not seen from above in perfect calices, and it is not revealed until a 

 section of the corallite is made. 



Localities. — Wc^ods Bluff, Grcggs Landing, and Prairie Creek, Alabama. 



Geologic occurrence. — Cliickasawan stagc. Tj'pes from Bells Landing beds. 

 Specimens referred to this species occur in the Woods Bluff and the Midway 

 beds. 



Types. — United States National Museum. 



Haimesiaste^a petrosa (dabb). 

 PI. XVII, figs. 1 to C. 



1864. Astrocoeniaf petrosa Gabb. Paleontology of California, Vol. I, p. 208, pi. xxxi, 



tigs. 274, 274a. ' 



1893. Astrocmnia f x)etrosu Boyle. Bibl. Invert. Foss., p. 54. 

 189G. Astroccenia petrosa Stanton. The fauual relations of the Eocene and Upi^er 



Cretaceous of the Pacific Coast: Seventeenth Ann. Eept. U. S. Geol. Survey, 



Pt. I, p. 102!t. 



This species is described here because it is of doubtful Eocene or 

 Cretaceous age. I wrote to Dr. J. C. Merriam, of the University of Cali- 

 fornia, for information concei'ning. the original locality of the species, and 

 he replied: "I am not at all certain about the original occpirence of this 

 species, but rather think it conies from some road ballast, brouglit from 

 no one knows where, by the raih'oad company." Gabb states (loc. cit.): 

 "All of the specimens were obtained from a single mass of limestone, a 

 mile west of Martinez." 



Dr. Meri'iam ^ery kindly sent me a portion of the original type 

 material of Gabb, and on it the following description is based. 



