CORALS AND BRYOZOA. 
133 
5 mm., on a plane with the branches or elevated above them! very frequently 
extending across the branch, uniting with adjacent dissepiments and forming 
prominent, irregular, transverse elevations, which are the most conspicuous 
feature of the frond and give to it a very irregular appearance. Fenestrules 
oval, length .50 mm. or more, width from .25 to .30 mm. 
On the celluliferous face the scalae have a width of .25 to .30 mm., twelve 
in the space of 5 mm.; summit of carina angular, slightly carinated, elevated 
above the scalae. 
This species most nearly resembles F. (77) stipata; on the non-celluliferous 
face the branches are more slender and much more irregular; the dissepiments 
more prominent: on the celluliferous face the scalae have broader summits, 
which are not oblique ; on the side of the carina the scalae are directed obliquely 
toward the base of the frond only, not bent as in F. ( U .) stipata and F. (JJ.) 
tegulata. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
FeNESTELLA (UnITRYPA) NANA, 11. Sp. 
NOT FIGURED. 
Bryozoum infundibuliform. Fronds small, rapidly expanding. Branches very 
slender, width above a bifurcation about .16 mm., increasing to .30 mm., 
straight, rounded or sub-angular; when perfectly preserved slightly carinated, 
when a little worn or marcerated, smooth; bifurcations frequent. Inter¬ 
stices wider than the branches. Dissepiments extremely slender, width .12 
mm., rounded, much expanded at their junction with the branches, slightly 
depressed, ten in the space of 5 mm. Fenestrules oval, length .38 mm., 
width .28 mm. 
On the celluliferous face the dissepiments are rounded, slightly carinated, 
very much depressed. Fenestrules narrower than on the opposite face. Cells 
in two ranges, opening outward, twenty in the space of 5 mm., separated by less 
than the diameter of an aperture : margins thin, indenting the borders of the 
fenestrules. Summit of carina .10 mm. in width ; scalae very thin, oblique, 
twenty-two in the space of 5 mm. 
