116 
PALAEONTOLOGY 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. 5, G. 
Fenestella sinuosa, Hall. Report of State Geologist for 1S85, advance sheets. Expl. pi. 44, tigs. 5, 6. 188(5. 
Bryozoum infundibuliform. Branches strong, width above a bifurcation .75 mm., 
increasing 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 
dejiressed. Fenestrules of about the same appearance as on the opposite face. 
Cell apertures in two ranges, fourteen in the space 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 tuberculata, n. sp. 
PLATE XLVI, FIGS. 25, 26, 33, 34. 
Bryozoum 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 
