63. CONTRIBUTION TO 



lix and gradually disappear; a few continues to the summit of the eone and ab- 

 ruptly ends, giving the surface of the cone a rugose appearance. Fossette con- 

 sists of a deep narrow groove, commencing on the anterior side of the elevated 

 tabulae, and continues to the margin of the calix. Denticulations fine, ten in 

 the space of six millimeters. 



Found in the Upper Devonian (Hamilton group) near Charlestown, Indiana. 

 Now in the collection of the author. 



CYSTIPHYLLUM MULTICRENATUM, N. Sp. 



Plate 22. Figs. 5, 6-7. 



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

 base of attachment, height varying in different examples, from forty to sixty 

 millimeters. Exterior with numerous annulations, and sharp constrictions, 

 caused by periodical growth. When decorticated, they have the appearance of 

 a number of thin, invaginated cups, with fine crenulated margins. Calix 

 broadly campanulate, from thirty-five to fifty millimeters in diameter. Depth 

 twenty-five millimeters; the bottom of the calix is comparatively smooth, 

 with a thin silicious coating of a white appearance. The lamelhe is very nu- 

 merous and well defined. Equal in size and broadly rounded at the margin, 

 growing narrower and thinner, and gradually disappears on reaching the smooth 

 space in the bottom of the calix. The vesicles in the calix have the appear- 

 ance of slight swellings, variable in size, those on the surface, when decorti- 

 cated, are more numerous and well defined. 



The broad rounded lamellai and the appearance of the crenulations on the 

 margins of the invaginated cups, gives it the decided appearance of a Chono- 

 phyllum. 



Found in the middle Devonian (Upper Helderberg group) at the Falls of 

 the Ohio, now in the collection of the author. 



ZAPHRENTIS OBSCURUS, N. Sp. 



Plate 22. Figs. 8-9-10. 



Corallum simple, turbinate, straight or regularly curved. Acute at the 

 base of attachment. Height varying in different individuals, fi'om forty to 

 sixty millimeters, regularly expanding in diameter to the calix. Exterior with 

 distant rounded annulations, and wrinkles, caused by intermittent growth. 

 Calix somewhat campanulate, from thirty to thirty-five millimeters in diameter. 

 Depth twenty millimeters. A convex space in the bottom of the calix', occupied 



