CORALS AND BRYOZOA. 
115 
there is a prominent conical node below each bifurcation. Interstices nar¬ 
rower than the branches. Dissepiments slender, width .20 to .25 mm , 
usually rectangular to the branch, but sometimes oblique, rounded, on a plane 
with the branches, eight or nine in the space of 5 mm. Fenestrules oval, 
length from .35 to .40 mm., width from .20 to .25 mm. 
On the celluliferous face the dissepiments are angular, depressed, com¬ 
paratively strong. Fenestrules narrower than on the opposite face. Cell 
apertures in two ranges, opening laterally, twenty in the space of 5 mm., 
separated by less than the diameter of an aperture : margins slightly elevated. 
Surface between the ranges of apertures angular, elevated. Below each bifur¬ 
cation, and sometimes on other portions of the branch, there is a strong node 
similar to those on the opposite face. 
This species may be distinguished by its prominent nodes which usually 
occur immediately below a bifurcation on both faces of the frond. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Fenestella proceritas, n. sp. 
PLATE XLVI, FIGS. 32, 35, 36. 
Bryozoum infundibuliform, fronds large. Branches slender, width above a 
bifurcation .25 mm., increasing to .50 mm., very gradually enlarging, the 
increase in size often scarcely perceptible, straight, rounded, with very fine 
granulose striations and small nodes; bifurcations distant. Interstices much 
wider than the branches. Dissepiments very slender, width .20 mm., 
rounded, finely striated, very slightly expanded, nearly on a plane with the 
branches, four in the space of 5 mm. Fenestrules sub-quadrangular, length 
from a little more than 1 mm. to 1.60 mm., width .45 or .50 mm. 
On the celluliferous face the branches are angular. Dissepiments angular 
and much depressed. Fenestrules somewhat narrower than on the opposite 
face. Cell apertures in two ranges, opening laterally, fifteen in the space of 5 
mm., separated by a little more than the diameter of an aperture: margins 
very thin, slightly elevated. Surface between ranges of apertures sharply 
angular, elevated about .18 mm. 
