168 



EOCENE AND LOWER OLIGOCENE CORAL FAUNAS. 



Localities. — Moutgomeiy, Louisiana; Jacksou, Mississippi ; and Claiborne, 

 Alabama. 



Geologic occurrence. — Jack.souian .stagc, ancl Upper Claiborne (?). 



Balanophyllia irrorata var. mortoni (Gabb aud Horn). 



PI. XIX, fig. 7, drawn from one of (iabb and Horn's types; PI. XIX, figs. S to 8b, from 

 a specimen with more pointed base, from Wagner Institute collection. 



1860. Trochosmilia mortoni Gabb and Boru. Jour. Acad. Nat. Sci. Phila., Vol. IV, 

 p. 389, pi. Ixix, figs. 4-6. 



The following description is based upon the original types: 

 Corallum of a short subcorneal form, cross section elliptical, slightly 

 curved. The curvature may be in the plane of the lesser or greater trans- 

 verse axis oi' the calice. Attached by a broad base when young, but 

 becoming free, and the scar may be ultimately almost obliterated. Co.st3e 

 well developed, but not so prominent as in B. irrorata; branch by trifurca- 

 tion. Intercostal fuiTOws perforated. A slight development of epitheca. 

 Wall strong, not very thick, slightly vesiculated. Septa in five cycles; 

 those of the fifth cycle uniting in front of those of the fourth. Columella 

 weak. 



Greater diameter of calice, about . 

 Lesser diameter of calice, about. .. 

 Height of corallum 



a Adult specimen, PI. XIX, fig. 7. 



Localities. — CaldwcU Couiity, Texas; Moseleys Feny, Brazos River, 

 Burleson County, Texas; Black Shoals, or Colhers Ferry, Brazos River, 

 Texas; Lexington, Lee County, Texas. 



Geologic occurrence. — Lowcr Claibome. 



Original types. — Philadelphia Academy of Natural Sciences. 



In PI. XIX, fig. 7, there is a young coral attached to an old corallum. 

 This shows very nicely the method of attachment of the young. In the 

 adult none of the expanded base persists, and the scar is healed over by a 

 subsequent calcareous deposit. The costfe resemble those of B. irrorata, 

 but they are not so coarse and are more acute. In tlie form of tlie corallum 

 the variety is variable; it is either rather elongate or rather short; the coral- 

 lum is shorter than in B. irrorata typical. 



