50 
PALAEONTOLOGY OF NEW YORK. 
On the celluliferous face the branches are angular and the dissepiments 
much depressed. The fenestrates appear somewhat narrower and more reg¬ 
ular than on the opposite free. Cell apertures small, circular, three in the 
length of a fenestrate, disposed in two ranges, opening laterally at an angle 
of forty-five degrees to the axis of the branch: margins elevated, slightly 
indenting the borders of the fenestrates. Between the ranges of apertures 
there is a line of nodes along the summit of the branch. 
Width of branches at first .25 min., increasing to .75 mm. Diameter of 
dissepiments from .16 to .18 mm.; length of fenestrates from .40 to .50mm. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
Fenestella Philia. 
PLATE XX, FIGS. 9-11. 
Fenestella Philia , Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 168. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 20, figs. 9-11. 1883. 
Bryozoum probably infundibuliform, and radially plicate. Branches slender, 
rounded and smooth, from twelve to sixteen in the space of 5 mm. Dissepi¬ 
ments slender, nine in the space of 5 mm. Interstices usually wider than 
the branches. Fenestrates sub-quadrangular. 
On the celluliferous face the branches are angular and marked by a line of 
nodes along the center. Cell apertures in two ranges, small, circular or sub¬ 
oval, three in the space of one fenestrule, distant from each other more than 
the diameter of an aperture. 
Formation and locality. In the shaly limestone of the Lower Helderberg 
group, near Clarksville, N. Y. 
Fenestella Tiiyene. 
PLATE XXI, FIGS. 1-5. 
Fenestella Thyene, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 170. 1879. 
Fenestella Thyene, Hall. Report of State Geologist for 1882. Expl. pi. 21, figs. 1-5. 1883. 
Bryozoum infundibuliform, growing directly from a spreading base without a 
pedicel. Branches moderately strong, angular, compactly arranged, straight 
