206 



NEW YORK STATE MUSEUM 



ones continuing to the center, straight or very slightly twisted; 

 between the septa at the center of the corallum a deposit of 

 stereoplasma, which has the appearance of a columella; tabulae 

 and dissepiments frequent. 



The pseudocolumella distinguishes this genus from Z a - 

 phrentis. 



LoPHOLASMA, gen. nov. 



Type: Streptelasma rectwm (in part) Hall. Illus. Devonian fos- 

 sils. 1876. pi. 19. Hamilton shales, western New York, 



Corallum conical, straight, sometimes slightly curved at the 

 apex, subrigid in appearance; surface with frequent annulations, 

 and numerous concentric striae; costae distinct, flat or slightly 

 rounded, the surface resembling that of Heliophyllum; 

 septal fovea well defined; septa alternating in size, the larger ones 



20 



Fig. 19 Lopholasma carinatum {nom. propos.) A transverse sec- 

 tion showing the pseudocolumella, the septa, dissepiments, and 

 the spur-like processes from the septa 

 20 Longitudinal section showing the pseudocolumella, septal carinae 

 and the delicate tabulae 



continuing to the center, where there is a deposit of stereoplasma 

 forming a pseudocolumella, which does not extend beyond the 

 bottom of the calyx. On the sides of the septa are strong, essen- 

 tially horizontal carinae, extending from the exterior wall to the 



