J86. CONTRIBUTION TO 



abruptly slope to the bottom of the calix, where the short ones gradually disap- 

 pear, the longer ones continue to the smooth convex space and abruptly termi- 

 nate. Denticulations fine, ten in the space of five millimeters. Fossette con- 

 sists of a slight depression at the margin of the. smooth convex space in the 

 bottom of the calix and extends to the margin of the cup; position variable. 



Found in the Lower Devonian (Corniferous group) at the Falls of the Ohio. 

 Now in the collection of the author. 



FAVOSITES LOUISVILLENSIS, N. Sp. 

 Plate 56. Figs. 2. 



Corallum composed of a thin convex disk. With a thin wrinkled epithecal 

 crust on the lower side. Tubes polygonal, unequal in size, from one to three mil- 

 limeters in diameter. Tube walls decorated with numerous longitudinal rows 

 of spines. Pores large, round from two to three rows on a side. Tabulae flat or 

 slightly oblique, in some places closely arranged, in other places more distant 

 apart. When the surface of the corallum is weathered the tubes have the ap- 

 pearance of being quadrangular or pentagonal in outline, and where the dia- 

 phragms come to the surface they appear pitted in the angles of the tubes as 

 seen in Favosites favosus. 



Found in the Upper Silurian (Niagara group) at the Work House Quarry, 

 on Beargrass Creek, near Louisville, Ky. Now in the collection of the author. 



ZAPHRENTIS S U B C E N T R AL I S , N. Sp. 



Plate 56. Figs. 3, 4, 5. 



Corallum simple, turbinate, straight or slightly curved. Acute at the point 

 of attachment. Height twenty-five millimeters. Gradually enlarging in diam- 

 eter to the calix. Exterior with numerous shallow annulations and wrinkles, 

 caused by intermittent growth. Calix rounded, somewhat campanulate, twenty 

 millimeters in diameter. Depth ten millimeters. Number of lamellae fifty-two, 

 in the circumference of a calix twenty millimeters in diameter, sharp and une- 

 qual in size at the margin, alternating below, the short ones reach to the bottom 

 of the calix and terminate, the longer ones continue to within one and a half 

 millimeters of the center and abruptly end, leaving a smooth, oblique, concave 

 space in the center of the calix three millimeters in diameter. Fossette con- 

 sists of a deep groove, commencing at the margin of the smooth oblique space, 

 and continues to the posterior margin. 



Found in the Upper Devonian (Hamilton group) at Speed's Quarries, Clark 

 county, Indiana. Now in the collection of the author. 



