9. CONTRIBUTION TO 



depression at the edge of the flat space in the bottom of the calix. and in some 

 examples extends to the anterior margin, in some others it does not extend so 

 far, but always conspicuous. 



This species resembles somewhat in external appearance Z. ischypus, but 

 differing essentially, in having thin sharp lamelhe, and concave tabulae; in that 

 species the tabube is more numerous and flat. 



Found in the Upper Devonian, (Hamilton group) near Charlestown, Indi- 

 ana. Now in the collection of the author. 



ZAPHRENTIS AMPLIATUS, N.Sp. 



Plate 4. Figs. 7, 8. 



Corallum simple, turbinate, straight, or slightly curved. A broad scar at 

 the base of attachment, occasionally extending some distance on the side of the 

 coral. Height thirty-five to sixty-five millimeters in the longest examples ob- 

 served. Calix broadly campanulate, somewhat funnel-ehaped, from twenty to 

 thirty-five millimeters in diameter. Depth twenty millimeters. A flat space 

 in the bottom of the cup, occupied by the tabulae, from three to ten millimeters 

 in diameter. Number of lamellae seventy, in the circumference of a cup, thirty 

 millimeters in diameter, alternating in length, rounded and sub-equal at the 

 margin, gradually sloping to the bottom of the calix ; the short ones terminate 

 on reaching the flat space, the longer ones become elevated, sharp, slightly twisted, 

 and continues to the center of the calix, and terminates, not elevated. Fossette 

 consists of a deep depression on the side of the flat space in the bottom of the 

 cup, and extends about half way to the anterior margin, and gradually disap- 

 pears. 



Found in the Upper Devonian, (Hamilton group) near Charlestown, Indi- 

 ana. Now in the collection of the author. 



CYATHAXONIACOMPRESSA, N.Sp. 



Plate 4. Figs. 14, 15, 16, 17. 



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

 of attachment. Height fifteen millimeters, for about ten millimeters com- 

 pressed, then gradually rounding to the margin of the cup. Exterior compari- 

 tively smooth, with a few shallow annulations and wrinkles caused by inter- 

 mittent growth. Diameter of calix four millimeters. With vertical walls. 

 Depth four millimeters. A flat space in the bottom of the calix two or three 

 millimeters in diameter. Situated in the center of the calix, is a smooth con- 

 vex cone, two millimeters in height. Number of lamella thirty, in a calix four 



