NEW GENEiRA OF PALEOZOIC RUGOSE CORALS 



205 



sides thin; septal fovea obscure, and in some species apparently 

 obsolete; septa alternating in size, the larger ones continuing 

 nearly to the center, having projections from their extremities 

 which continue to the center, becoming much involved, forming 

 a pseudocolumella of very peculiar appearance, somewhat re- 

 sembling the convolutions of the intestines; sides of the septa 

 with numerous papillate elevations or carinae, which in a trans- 

 verse section give to the septa a crenulate or echinate appear- 

 ance; tabulae and dissepiments present. The characteristic fea- 

 ture of this genus is the peculiar appearance of the pseudo- 

 columella. 



Stereolasma, gen. nov. 



Stromhodes? rectus Hall. Geol. rep't 4th district N. Y. 1843. 

 p. 209, fig. 5. 



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

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



Pig. 16 Stereolasma rectum [Hall). A transverse section showing 

 isepta, dissepiments, and pseudocolumella 



17 A longitudinal section showing tabulae and pseudocolumella 



18 S. u n g u 1 a {Hall). A longitudinal section 



Example: Streptelasma ungula Hall. Hlus. Devonian fossils. 

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



Corallum varying in size, straight or curved, simple; calyx circu- 

 lar; septal fovea conspicuous; septa alternating in size, the larger 



