Upper Helderberg Group. 453 



diameter of calix 40 mm., depth 20 mm.; an elevated space at the bottom 

 10 mm. in diameter; fossette small ; number of lamellae 80, thin, of 

 nearly uniform size at the margin of the calix, alternating below ; the 

 principal lamellae extending to the center of the cup twisted and 

 elevated, forming a false columella ; denticulations very prominent, 4 

 or 5 in the space of 5 mm. 



Formation and locality. Corniferous limestone, Falls of the Ohio. 



Heliophyllum fecundum, n. sp. 



Corallum small, increasing by calicular gemmation, sometimes con- 

 nected for nearly their entire length ; height of an adult individual 25 

 mm.; diameter of calix 13 mm.; for a distance of 4 mm. from the mar- 

 gin the walls of the cup are nearly flat, then abruptly descending to a 

 plane, smooth area 4 mm. in diameter at the bottom of the calix ; num- 

 ber of lamellae 70, of uniform size, extending to the flat space at the 

 bottom of the calix ; denticulations minute; no fossette. From one 

 calix, only 12 mm. in diameter, proceed 5 buds. From H. gemmatum 

 it is easily distinguished by its smaller size and entirely different form 

 of calix. 



Formation and locality. Corniferous limestone, Falls of the Ohio. 



Heliophyllum gemmatum, n. sp. 



Corallum rapidly increasing in numbers by calicular gemmation ; 

 height usually from 25 to 30 mm.; diameter of calix 20 mm., depth 10 

 mm.; sides quite regularly sloping ; a space at the bottom of the calix 

 3 mm. in diameter flat, smooth; number of lamellae 70, sometimes of uni- 

 form size, at others alternating, extending to the flat space at the center 

 of the calix ; denticulations minute, 16 in the space of 5 mm.; fossette 

 small. In nearly all the individuals observed there are from 3 to 5 

 buds growing from the parent corallum. 



Formation and locality. Corniferous limestone, Falls of the Ohio. 



Heliophyllum latericresceks, n. sp. 



Corallum sub-cylindrical, slightly compressed, simple or compound^ 

 increasing by lateral gemmation ; exterior with numerous sharp annu- 

 lations of growth, concentric wrinkles and fine striae ; largest speci- 

 men observed 10 centimetres in length, having a nearly uniform 

 diameter of 30 mm.; depth of calix 15 mm., somewhat bell-shaped, 

 center elevated ; number of lamellae from 90 to 100, uniform in size 

 near the margin of the cup, alternating below ; the principal ones, ex- 

 tending to the center of the cup, are twisted and elevated, forming a 

 false columella ; denticulations fine, 18 in the space of 5 mm. In its 



