15. CONTRIBUTION TO 



HELIOPHYLLUM NILESI, N. Sp. 



Plate 5. Figs. 2, 3. 



Corallum simple, or composite, increasing by parietal budding. Attenuate 

 at the base of attachment. A short distance above the base, short root-like 

 processes sets out for attachment or support. Height of corallites forty milli- 

 meters. Diameter of calix twenty millimeters, and somewhat funnel-shaped. 

 Depth fifteen millimeters. A smooth depressed space in the bottom of the calix, 

 occupied by the tabular, four millimeters in diameter. Number of lamellae six- 

 ty-four, in the circumference of a calix, twenty millimeters in diameter, thin, 

 and slightly unequal in size at the margin, alternating below, gradually slop- 

 ing, to within five or six millimeters of the smooth space in the bottom of the 

 calix, where the short ones terminate, the longer ones coalesces, and continues 

 to the smooth space, and abruptly ends, leaving a smooth depressed space in 

 the bottom of the calix, four millimeters in diameter. Denticulations fine, con- 

 spicuous, nine in the space of five millimoters. Fossette consist? of a narrow 

 groove, commencing at the edge of the smooth space in the bottom of the calix, 

 and continues to the margin of the cup; position variable. Exterior very rug- 

 ged, when decorticated they have the appearance of .thick invaginated cups. 

 Base of the corallites, when not in contact with the parent cup, are smooth and 

 round, appears as if turned in a lathe. 



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

 specific name is in honor of Prof. W-hj. H. Niles, professor of Geology in the 

 Massachusetts School of Technology, Boston, Massachusetts. Now in the col- 

 lection of the author. 



HELIOPHYLLUM T U R GI D U M, N. Sp. 



Plate 5. Figs. 4, 5. 



Corallum simple, broadly sub-turbinate, straight, or gradually curved. 

 With a broad scar at the base of attachment, rarely acute at the base. Height 

 thirty millimeters. Rapidly expanding in diameter to the calix. Exterior with 

 a few strong annulations, and wrinkles caused by intermittent growth. Calix 

 oblique, broadly campanulate, forty millimeters in diameter. Depth ten milli- 

 meters. A convex space, slightly elevated, in the bottom of the calix, occupied 

 by the tabular, ten millimeters in diameter. Number of lamella?, varying in 

 different individuals, from one hundred and thirty to one hundred and fifty, in 

 the circumference of a calix, forty millimeters in diameter, alternating in length, 

 sub-equal at the margin, for about five millimeters nearly flat, then gradually 

 elope to the bottom of the calix, where the short ones become thinner and grad- 

 ually disappear, the longer ones continues to the convex elevation, slightly 



