58 
PALAEONTOLOGY OF NEW YORK. 
node opposite the dissepiments. Width of the interstices about equal to that 
of the branches. Dissepiments very slender, angular, slightly depressed 
below the plane of the branches, eight in the space of 5 mm. Fenestrules 
sub-quadrangular, width from one-half to two-thirds the length. 
On the celluliferous face the branches are angular and the dissepiments 
rounded and depressed. The fenestrules appear more oval in form than on 
the opposite face. Cell apertures small, circular, in two ranges, opening 
directly outward, twenty-five in the space of 5 mm., distant less than the 
diameter of an aperture: margins elevated and indenting the borders of the 
fenestrules. Branches carinated; the summits of the carinae are expanded, 
angular and connected by lateral processes which meet midway between the 
branches, coalesce and form a flattened zigzag ridge. The lateral processes 
correspond in number and are situated over the cell apertures. The inter¬ 
stices are oval, and wider than long. 
Width of branch above a bifurcation .20 mm., increasing to .50 mm.; dis¬ 
sepiments from .18 to .20 mm. in diameter ; length of fenestrules from .40 
to .60 mm.; height of carina .20 mm. 
This form differs from F. (II.) biseria.lis in its more delicate growth, smaller 
branches, and the more slender and closely arranged dissepiments. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
POLYPORA, McCoy. 1845. 
Fenestella (Polypora) Eudora. 
PLATE XIX, FIGS. 3,4,5? 6-10. 
Fenestella Eudora, Hall. Thirty-second Rept, N. Y. State Mus. Nat. Hist., p. 165. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 19, figs. 3-10. 1883. 
Bryozoum broadly infundibuliform, growing from a very slender pedicel, 
having a diameter less than 1 mm. Branches moderately slender, very 
gradually increasing in size to the bifurcations, which occur at intervals of 
from 3 to 15 mm., and are more frequent near the base than above. On the 
non-celluliferous face the branches are rounded, sometimes flattened just 
below a bifurcation, marked by from five to seven very fine, distinct striae 
