CONTRIBUTION TO 



This species resembles somewhat H. Tumidulum, but differs in the coa- 

 lescing of the lamelhe adjacent to the fossette, and the elevation in the bottom 

 of the calyx is not so conspicuous. 



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

 now in the collection of the author. 



HELIOPHYLLUM TUMIDULUM, N. Sp. 



Plate 1, Figs. 5-6-7. 



Corallum small, simple, oblique, sub-turbinate, with a broad scar at the 

 base of attachment, height tw^enty to twenty-five millimeters. Diameter twenty 

 to twenty-five millimeters. Depth fifteen millimeters. Longitudinal strife 

 distinct. Exterior with constrictions and sharp annulations, caused by inter- 

 mittent growth. Number of lamellae eighty, alternating in size and length; 

 the shorter ones gradually disappear before reaching the bottom of the cup. 

 The longer ones are rounded at the margin, growing thinner as they approach 

 the center of the calyx, coalescing and twisting into a small prominence, two 

 or three millimeters in height. Denticulations r>oarse, slightly elevated above 

 the lamella?. Fossette well defined, consist of a deep depression at the base of 

 the elevation in the bottom of the calyx, and continues to the anterior margin. 



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

 ana. Now in the collection of the author. 



ZAPHRENTIS HUMILIS, N. Sp. 



Plate 1, Figs. 8—9. 



Corallum small, simple, turbinate, straight, or regularly curved, acute at 

 the base of attachment, gradually expanding in diameter to the calyx. Exte- 

 rior with sharp annulations and wrinkles caused by intermittent growth. 

 Height twenty-five millimeters . Calyx bell-shaped, fifteen millimeters in di- 

 ameter. Depth ten to twelve millimeters; a flat space in the bottom of the cup, 

 occupied by the tabuhe, ten millimeters in diameter. Number of lamelke sev- 

 enty to seventy-six in the circumference of a calyx fifteen millimeters in diam- 

 eter, thickened and rounded at the margin, growing thinner and elevated, as 

 they gradually descend to the bottom of the calyx, where the short ones termi- 

 nate. The longer ones continue to near the center of the cup, and abruptly 

 end, leaving a flat space from two to five millimeters in diameter. On the 

 posterior side there is one principal lamelhv elevated above the others that ex- 

 tends to the edge of the fossette. In some examples it does not extend so far, 

 but abruptly ends in the center of the cup. Fossette conspicuous, consist of a 



