450 Thirty-fieth Keport on the State Museum. 



Heliophyllum incrassatum, n. sp. 



Oorallum simple, turbinate, height 40 mm.; diameter of the calix 30 

 mm., depth 15 mm., sides near the margin flat or rounded, then quite ab- 

 ruptly descending, a space at the bottom 10 mm. in diameter flat; 

 fossette conspicuous; number of lamellae 56, alternating in size, the 

 smaller ones being about one-third the thickness of the others ; the 

 greater portion of the lamellae extend only to the flat space at the bot- 

 tom of the calix, from that point about 15 are very much thickened 

 and extend to the center, straight or slightly flexuous ; denticulations 

 moderately prominent, from 6 to 8 in the space of 5 mm., near the 

 margin wide, becoming narrow and spiniform below. 



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



Heliophyllum acuminatum, n. sp. 



Oorallum simple, turbinate, regularly curved, length of anterior 

 side 50 mm., of posterior 25 mm.; diameter of the calix 40 mm., depth 

 30 mm., a space at the -bottom, 25 mm. in diameter, depressed convex ; 

 fossette conspicuous, extending from the convex space at the bottom 

 to the anterior margin ; number of lamellae 80, alternating in size, 

 margins broadly angular; the larger ones extend upon the tabulae, but 

 do not reach the center; denticulations very prominent, sometimes 

 extending nearly 1 m. beyond the margins of the lamellae, from 3 to 4 

 in the space of 5 mm. 



Formation and locality. Corniferous limestone, Ontario. 



Heliophyllum vekatum, n. sp. 



Oorallum simple, turbinate, regularly curved ; exterior with sharp 

 ridges of growth; height of corallum 40 mm.; diameter of calix 35 

 mm., depth 15 mm., a space at the bottom, 20. mm. in diameter, de- 

 pressed convex; fossette conspicuous, situated on the anterior side; 

 number of lamellae 90, alternating in size, the larger ones continuing to 

 the center of the calix, becoming flexuous or slightly twisted, adjacent 

 ones frequently coalescing ; denticulations prominent, 5 in the space 

 of 5 mm. 



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



Heliophyllum imbricatum, n, sp. 



Corallum sub-cylindrical or elongate turbinate, gradually expanding ; 

 exterior with numerous sharp ridges of growth ; when decorticated 

 the internal costae present a peculiar imbricated appearance, the imbrica- 

 tion being toward the base ; diameter of calix from 30 to 40 mm., 

 depth 15 mm., a space at the bottom 15 mm. in diameter flat ; fossette 

 conspicuous, extending from near the center to the margin ; number 



