44 
PALEONTOLOGY OF NEW YORK. 
On the celluliferous face the branches are angular and the dissepiments 
depressed. Cell apertures moderately large, circular, in two ranges opening 
laterally; eighteen in the space of 5 mm., with interspaces equal to the 
diameter of an aperture. There is usually an additional aperture imme¬ 
diately below a bifurcation. When the specimen is somewhat worn or mac¬ 
erated, the apertures appear larger, more closely arranged, and open more 
upon the side of the branch. 
Width of branches above bifurcation .25 mm., increasing to .50 mm. ; 
diameter of dissepiments .20 mm.; length of fenestrules from .75 to .80 mm. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
Fenestella junceus. 
PLATE XX, FIGS, 16-ltj. 
Fenestella junceus, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 168. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 20, tigs. 16-18. 1883. 
Bryozoum infundibuliform, gradually expanding. Branches slender, slowly 
increasing in size; rounded and marked by from six to seven strise on 
each branch. Width of the interstices about equal to that of the branches. 
Dissepiments slender, rounded, striated, very slightly expanding at their 
junction, and on the same plane with the branches. Fenestrules elongate, 
sub-quadrangular. 
On the celluliferous face the branches are angular and the dissepiments 
much depressed. Fenestrules of the same appearance as on the opposite 
face. Cell apertures comparatively large, circular, in two ranges, opening 
laterally; twenty-five in the space of 5 mm.; separated by a distance equal 
to the diameter of an aperture ; margins slightly elevated. 
Width of a branch above bifurcation .30 mm., increasing to from 50 to 
.60 mm.; diameter of dissepiments .25 mm.; length of fenestrules gener¬ 
ally 1 25 mm., sometimes 1.50 mm., width from .25 to .40 mm., usually 
about .33 mm 
Formation and locality. Lower Helderberg group, Clarksville, N. Y. 
