116 PALEONTOLOGY OF NEW YORK. 



This species may be easily distinguished by its slender branches, of essen- 

 tially the same size for nearly their entire length, and the large, sub-quadran- 

 gular fenestrules. 



Formation and locality. Upper Helderberg group, Walpole, Ontario, Canada. 



Fenestella sinuosa. 



PLATE XLIV, FIGS. B, C. 

 Fenettella sinuoaa. Hall. Report of State Geologist for 1885, advance sheets. Exiil. pi. 44, K^. 5, ti. 1886. 



Bryozoum infundibuliform. Branches strong, width above a bifurcation .75 mm., 

 incre.ising to 1.25 mm., sinuous, angular, slightly carinated. Interstices from 

 slightly narrower to wider than the branches. Dissepiments strong, width 

 .60 mm., angular, carinated, depressed, ten in the space of 5 mm. Fenes- 

 trules oval, length about 1.35 mm., width usually from .60 to .75 mm. 



On the celluliferous face the dissepiments are rounded, carinated, much 

 depressed. Fenestrules of about the same appearance as on the opposite face. 

 Cell apertures in two ranges, fourteen in the sp.ace of 5 mm., separated by one- 

 half the diameter of an aperture. Branches carinated, carinoe thin, prominent, 

 height, .25 mm. 



The non-celluliferous face of this species so closely resembles that of F {Poly- 

 pora) robusta, that it is difficult to distinguish the two ; but the celluliferous face 

 has, of course, only a remote resemblance to that species. 



Formation and locality. Upper Helderberg group, near Caledonia, N. Y. 



Fenestella tdberculata, n. sp. 



I'LATE XbVl, FIGS. 25, 26, 33, 34. 



Bbyozoum infundibuliform, fronds large. Branches moderately slender, very 

 gradually enlarging, width above a bifurcation .30 mm., increasing to .60 mm., 

 straight, abruptly rounded or sub-angular, with frequent, prominent, conical 

 nodes, irregularly disposed and forming the most characteristic feature of the 

 frond. Interstices wider than the branches. Dissepiments very slender, 

 width .20 mm., rounded, slightly expanded, depressed below the plane of the 



