68 



EOCENE AND LOWER OLIGOCENE CORAL FAUNAS. 



eight or nine prominent radiating- riljs, with reguhxrly concave interspaces. 

 Upper surface unknown." 



Mr. T. W. Stanton collected near Benicia, California, many casts and 

 • specimens of this species embedded in sandstone. From the study of this 

 material the following description has been prepared: 



Form cuneate, triangular, and compressed; the cross section shows 

 acute, alajform projections at the ends of the longer transverse akis. On the 

 sides in the upper portion of the coralluni there are nine subacute prominent 

 costse, along the crests of which are usually minute tubercles; in the lower 

 portion of the corallum the costaj are very indistinct. Occasionally between 

 the prominent costse are fainter ones. The septa in a section of a corallum 

 that was studied were thin, 78 or 81 in number. There were only 22 of the 

 fourth cycle, it being incomplete between one septum of the first cycle and 

 the septum of the second cycle, which corresponds to the middle of one lat- 

 eral face. There were 32 septa of the fifth cycle, intercalated in the systems 

 between the primary septa at the ends of the longer transverse axis and the 

 primaries standing nearest the middle of the lateral faces. Apparently there 

 are a few members of the sixth cycle in two of the systems next the termini 

 of the longer transverse axis. The sides of the septa are granulate. Lower 

 portion of corallum entirely filled by calcareous deposit. Columella parietal. 



Longer transverse axis of caliee . 

 Shorter transverse axis of caliee . 

 Height of corallum 



21 



8 



Mm. 

 14 



11 



Locality. — Army Point, near Benicia, California. 



Horizon. — "Martinez and Tejon." (Dr. J. C. Merriam.) 



Specimens. — Uuited Statcs Natjoiial Museum. 



The character of the costfe and the ahieform projections are the best 

 criteria by wliicli to separate this species from the triangular varieties of 

 F. cuneiforme, to which it is closely related. 



