106 EOCENE AND LOWER OLIGOGENE CORAL FAUNAS. 



These measurements represent the usual size of adult specimens. Sev- 

 eral varieties, with sizes indicated, are figured in PI. VIII, figs. 11 to 14 



Localities. — Near Mount Lebanon, Louisiana; Holstun's well, Louisiana; 

 SW i of SE. 1 sec. 19,T. 19 N., R.7 W., Louisiana; Rayburn's well, sec. 29, 

 T. 17 N., R. 5 W., Bienville Parish, Louisiana; Newton, Enterprise, and 

 Wautubbee, Mississippi; 3 miles northeast of Newton, ]\Iississi})pi; 2 miles 

 southeast of Hickory, Newton County, Mississippi; 8 miles south of Hickory, 

 Clarke County, Mississippi; 8 miles west of Enterprise, Mississippi; 1 mile 

 south of Hickorv, Mississippi; 4.\ miles east of Newton, Mississippi; upper 

 layer, Sowilpa Creek, Alabama; Smith ville, Texas; Black Shoals, or 

 Colliers Ferry, 1 mile below the Milam-Burleson county line, Texas; Lex- 

 ington, Lee County, Texas. 



Geologic occurrence. — Lowcr Claibome (Llsbou horizon). 



Types. — b'nited States National Museum. 



Specimens. — Museiuu of Comparatlvc Zoology, Cambridge, Mass.; T. H. 

 Aldrich's collection; and Wagner Free Institute of Science. 



Additional notes on the wall septa, etc. — Tlic Wall IS a pseudotlieca, i. c., fomied by 

 the fusion of the distal ends of the septa. The septa have thickenings at 

 right angles to the septal plane in the nmral region. A thickening from 

 one septum meets that of the opposed septa, and the two fuse. A little line, 

 indicating tlie jilace of fusion, could be seen between nearly every pair of 

 septa in the cross section. The septal thickenings to form the wall are not 

 usually exactly in a ring, but the thickening on one side of a septum may 

 be interior or exterior to the thickening on the other side. 



The septa are composed of completely fused ascending trabeculse, 

 which possess a line of divergence coinciding in position with the wall. 

 The courses of the trabecuhx; are indicated by rows of granules. Tlio rows 

 on opposite sides of a septum do not stand opposite, but alternate in posi- 

 tion. The septal margins interior to the wall are entire ; exterior to it the 

 trabeculse frequently project slightly along their axes, making obscure den- 

 tations. No svnai)ticula} were seen; the septa are usually rather far apart, 

 so the granules do not fuse across the interseptal loculi. 



Three minor varieties of this species may be recognized, but they are 

 not of sufficient importance to merit naming. Variety a, the typical form 

 represented bv PI. VIII, fig. 11; variety ft, the specimen with very wide 

 base and low rounded costa^, represented by PI. VIII, fig. 14; variety 



