154 
PALAEONTOLOGY OF NEW YORK. 
.20 mm., angular, slightly carinated, much depressed below the plane of the 
branches, about live in the space of 5 mm. Fenestrules oval, length about 
.80 mm., width from .35 to .40 mm. 
On the celluliferous face the branches are rounded Dissepiments angular, 
slightly carinated, much depressed. Fenestrules a little narrower than on 
the opposite face. Cell apertures in two and three ranges, opening outward, 
sixteen in the space of 5 mm., separated by less than the diameter of an 
aperture, outer ranges slightly oblique to the axis of the branch; margins 
unequally elevated, the upper portion being the strongest: the apertures 
apparently open obliquely toward the base of the frond. Ranges of apertures 
separated by tine, slightly elevated, but very distinct ridges. 
This species has a general resemblance to F. (P.) elongata, but the branches 
and dissepiments are smaller and more closely disposed, there being two dis¬ 
sepiments in the space occupied by one in that species. 
Formation and locality. Upper Helderberg group, near Buffalo, N. Y. 
Fenestella (Polypora) granilinea. 
PLATE X^, FIGS. 20-23. 
Fejiestella granilinea , Hall. Trans. Albany Institute, vol. x, abstract, p. 27. 1881. 
“ (Polypora) granilinea, Hall. Report of State Geologist for 18S5, advance sheets. Expl. pi. 40, 
figs. 20-23. 18S6. 
Bryozoum infundibuliform, fronds large, compact. Branches slender, width 
above a bifurcation .38 mm., increasing to .55 or .60 mm., very gradually 
enlarging, essentially parallel, angular, with a row of granules along the 
middle resembling a carina, occasionally there are two or three lines of 
granules below bifurcations; bifurcations distant, usually occurring at inter¬ 
vals of from 30 to 50 mm. Interstices slightly narrower than the branches. 
Dissepiments slender, width .25 mm., rounded or angular, slightly depressed 
below the plane of the branches, eleven in the space of 10 mm. Fenes¬ 
trules oval, length .65 mm., width .40 mm. 
On the celluliferous face the branches are sub-angular. Dissepiments 
angular, carinated, depressed. Fenestrules narrower than on the opposite 
