INDIANA PALEONTOLOGY. 48, 



ACROPHYLLUM RUGOSUM, N. Sp. 



Plate 17. Figs. 1-2-3. 



Corallura simple, turbinate, or sub-turbinate, or sometimes conico-eylindri- 

 cal, straight or irregularly curved. Acute at the base of attachment. Height 

 varying in different individuals, from forty millimeters in small compressed ex- 

 amples, to seven inches in long horn-shaped or conico-cylindrical forms-. The 

 smaller examples, are usually in a better state of preservation, and exhibit 

 numerous small spines near the point of attachment, and frequently extend for 

 one or two inches above the base. Exterior, with more or less strong, rounded 

 annulations, and deep constrictions, and wrinkles, caused by periodical growth. 

 Calix somewhat expanding, rarely, though sometimes are circular, in this case, 

 they have steep side walls. In the examples with expanded calix, the walls grad- 

 ually slope to the bottom of the cup. Diameter of calix, varies from twenty to 

 thirty-five millimeters, in the broadest examples observed. Depth from ten to 

 twenty millimeters. Situated in the bottom of the calix, is a conical elevation, 

 five millimeters broad at the base, and five millimeters in height, caused by the 

 elevation of the tabulae. Number of lamellae, ninety, in the circumference of a 

 calix, thirty millimeters in diameter, equal in size, and sharp at the margin, al- 

 ternating below, gradually, or in some examples, rapidly sloping tb the bottom 

 of the calix, where the short ones disappear, or coalesces with the longer ones, 

 then continues a short distance, and coalesces again, and a few continues coales- 

 cing with the elevated tabulse. Fossette consists of a deep depression at the base 

 of the conical elevation, and continues to the margin of the calix. Position vari- 

 able. 



Found in a silicified condition in the lower Devonian (Corniferous group) 

 at the Falls of the Ohio. Now in the collection of the author. 



CHONOPHYLLUJ^ TYPICUM, N. Sp. 



Plate 18. Figs. 3-4-5. 



Corallum simple, turbinate, straight or curved, with a broad scar at the 

 base of attachment. This peculiarity is more strongly marked in some exam- 

 ples than in others; occasionally the scars extend a short distance on the side of 

 the coral ; in these examples, small root-like processes set out, having the appear- 

 ance of being attached to some foreign object. Regularly expanding in diameter 

 to the calix. Height varying from ten to fifty millimeters. Exterior covered with 

 a strong, wrinkled, epithecal crust, with a few broad, rounded annulations and 



