13. CONTRIBUTION TO 



inches. More or less curved, with a stout, wrinkled epitheca, and a broad scar 

 at the base of attachment, but in some cases they are pointed. The exterior is 

 rugged, undulated, and constricted, and presents an invaginated appearance. 

 A specimen well preserved, and an inch in diameter, will have a calix, an inch, 

 or more in depth, in the form of a conical cup; the cysts are large, though 

 somewhat variable in size ; they are as large internally as they are on the ex- 

 terior. In some specimens, the corallum appears as a mass of cysts, without 

 any evidence of septa, but in other specimens, when the cysts do not cover 

 completely the interior of the calix, fine rudamentary septa can be plainly dis- 

 tinguished; in such cases there are from eighty to one hundred septa in a calix 

 one inch in diameter. 



This species is easily distinguished in the simple state by the epitheca, and 

 the strongly marked base of attachment ; it is also distinguished by the rugged, 

 constricted, and invaginated appearance, and large cysts. 



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

 ana. Now in the collection of the author. 



CYSTIPHYLLUM L A C IN I AT U M, N. Sp. 



Plate 6. Figs. 10, 11, 12. 



Corallum simple, turbinate, more or less curved. Acute at the base of at- 

 tachment. Gradually, or at times rapidly expanding to the calix. Height 

 varying in different individuals from three-fourths to three inches or more. The 

 exterior is very rugged, and constricted, and appears as if composed of thin in- 

 vaginated cups. The calix appears as a hemispherical cup, having a depth 

 equal to one-half or more, of the diameter. The cysts are medium in size in 

 the calix, but larger externally. The septa is thin and numerous ; rudimentary 

 septa may be distinguished in the calix of nearly all specimens. 



This species differs essentially from C. ossiculum in its more rapidly ex- 

 panding to the calix, and is not as rough externally, and the cysts are smaller, 

 the cups are thinner in this species, than in that, and the calix is deeper. 



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

 ana. Now in the collection of the author. 



HELIOPHYLLUM BORDEN I, N. Sp. 



Plate 4. Figs. 9, 10. 



Corallum simple, or compound, increasing by calicular gemmation. Exter- 

 ior of parent cup with rough annulations, and wrinkles, caused by intermittent 

 growth. Height varying from twenty to fifty millimeters. Acute at the base 



