Uvper Helderberg Group. 



171. 



mm. ; cells in two ranges twenty in the space of 5 mm. ^ space between 

 ranges a nodose elevation, nodes strong and variable. 



Locality — Falls of the Ohio river. 



Fenestella pertenuis, n. sp. 



Infnndibuliform, width of branches from .20 to .25 mm., non-cellu- 

 liferous side sharply rounded with low conical nodes; dissepiments, 

 a little less than the width of the branches ; fenestrules quadrangu- 

 lar, length .35, width .25 mm., on celluliferous side .20 mm.; cells 

 in two ranges apertures circular, twenty-eight in the space of 5 mm.; 

 space between ranges one third the width of branch, elevated, with 

 prominent conical nodes. 



Locality — Falls of the Ohio river. 



Fenestella singularis, n. sp. 



Infnndibuliform; width of branches from .35 to .50 mm., on non- 

 celluliferous side rounded, with from three to five rows of granules 

 and occasional spines, immediately below each bifurcation is a strong 

 node or spine; dissepiments, from .25 to .35 mm. wide, sometimes 

 oblique to the branch ; fenestrules, oval or subquadrangular, length, 

 .50; width, .35 mm.; cells in two ranges; apertures circular, twenty 

 in the space of 5 mm.; space between ranges one-third the width of 

 branches, elevated, occasionally spinose. 



Locality — Falls of the Ohio river. 



Fekestella curvijunctura, n. sp. 



Width of branches from .20 to .50 mm.; shape varying from nearly 

 flat to acutely angular, sometimes having strong conical nodes; dis- 

 sepiments from two-thirds to three-fourths the width of the branch, 

 frequently curved, nodose; fenestrules, subquadrangular, length .25, 

 width .20 to .25 mm.; cells in two ranges; apertures circular, twenty- 

 five in 5 mm., space between ranges, elevated, having conical nodes 

 equal in number to cells. 



Locality — Falls of the Ohio river. 



Fenestella cultrata, n. sp. 



Infundibuliform; width of branches from .50 to .80 mm., round or 

 angular, with fine obscure granulose stride ; dissepiments, .30 to .68 

 m.m. wide; fenestrules usually subquadrangular, usual length .2 mm., 

 width from .25 to 1 mm.; cells in two ranges; apertures large, sixteen 

 to eighteen in 5 mm.; branch carinated, carina broad at base, con- 

 cealing apertures, narrowing above and sharp at the summit. 



Locality — Falls of the Ohio river. 



