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PALAEONTOLOGY OF NEW YORK. 
ranges, opening outward, twenty-two in the space of 5 mm.; closely disposed ; 
margins thin, distinctly elevated. Surface between ranges of apertures cari- 
nated ; carinae thin, height .60 mm., summits frequently sinuous ; scalae very 
thin, fourteen in the space of 5 mm., directed obliquely away from the 
base for a short distance, then abruptly bending and continuing toward the 
base, the latter portion having twice the depth of the former. Fenestrules 
narrow, elongate oval. Summit of carina not elevated above the scalae. 
The celluliferous face of this species closely resembles that of F. (17.) fastigata, 
but the dissepiments of that species, so far as observed, are never elevated above 
the branches, and there is frequently a slight elevation around the fenestrules. 
The scalae of both species, near the surface, are obliquely directed from the 
base, but those of this species are more closely disposed, there being fourteen 
in the same space occupied by six in that one. From F. (17.) stipata it may 
be distinguished by its somewhat coarser and more regular aspect, its larger 
fenestrules, its thinner and more oblique scalae. The summit of the carina is 
thin and not elevated above the scalae. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Fenestella (Unitrypa) lata. 
PLATE LII, FIGS. 1-10. 
Fenestella ( Hemitrypa) lata. Hall. Trans. Albany Institute, vol. x, abstract, p. 34. 18S1. 
Unitrypa spatiosa, Hall, in error. Report of State Geologist for 1884. PI. 2, fig. 12. 1885. 
Biiyozoum infundibuliform, fronds large, with frequent, broad, radial undulations 
or folds. Branches slender, width above a bifurcation .30 mm., increasing 
to .50 mm., very gradually enlarging, often the same size for nearly the entire 
length, rounded or flattened, nodose ; nodes small, conical, sometimes forming 
a row along the middle of the branch, at other times irregularly disposed; 
bifurcations distant. Interstices as wide as the branches. Dissepiments 
slender, width .25 to .30 mm., rounded, on a plane with the branches, four 
in the space of 4 mm., carinated; carinae thin, slightly elevated, but very 
distinct. Fenestrules oval, length .70 to .75 mm., width .35 mm. 
On the celluliferous face the dissepiments are rounded, carinated, much 
depressed. Fenestrules narrower than on the opposite face. Cell apertures 
