45. CONTRIBUTION TO 



millimeters. Depth thirty millimeters, with a smooth oblique, concave space 

 in the bottom of the calix, occupied by the tabulae, ten millimeters in diameter,. 

 Number of lamella?, one hundred, to one hundred and ten, in the circumference- 

 of a calix, forty millimeters in diameter, very thin, and sharp, equal in size at 

 the margin, alternating below, gradually or sometimes rapidly sloping to the- 

 edge of the smooth concave space, in the bottom of the calix, where the short- 

 ones abruptly terminate, the longer ones extend a short distance further, and! 

 blends with the tabuke, and disappears, leaving a concave space, in the bottom- 

 of the calix, from six to eight millimeters wide. Fossette consists of a deep de- 

 pression, situated at the edge of the concave space in the bottom of the cup, 

 and extends to the anterior margin. 



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

 Now in the collection of the author. 



CYSTIPHYLLUM L OUI S VILLE N S I S. N. Sp. 



Plate 16. Figs. 7-8-9-10. 



Corallum simple, turbinate, or broadly subturbinate, usually straight. 

 Acute at the base of attachment, near the base there is slender, root like, pro- 

 longations, which served as attachment to other objects for support. Height 

 varying in different individuals from fifteen to fifty millimeters. Calix broad, 

 shallow, from twenty to forty millimeters in diameter. Depth ten millimeters. 

 The entire surface of the calix, is covered with moderately large, somewhat 

 uniform sized cysts. When the calix is fairly preserved, the cysts are covered 

 with fine striae, but is not so strongly pronounced, as to appear as lamellae. Ex- 

 terior when decorticated shows the vesicles to be oblong in shape, and irregular 

 in size, the large ones being more concave than the smaller ones, occasionally 

 from two to four course elevated lines can be observed in the large oblong con- 

 cave vesicles. 



Found in the upper Silurian (Niagara group) at the Bear-grass creek quar- 

 ries, near Louisville, Ky. Now in the collection of the author. 



CYSTIPHYLLUM EXPANSUM. N. Sp. 



Plate 17. Figs. 6-7-8. 



Corallum simple, broadly sub-turbinate. Acute or slightly thickened at 

 the point of attachment. Rapidly expanding into abroad shallow cup. Length 

 on anterior side, fifty-five millimeters. Length of posterior side, twelve milli- 



