OF DENISON UNIVERSITY. 69 
On the reverse the branches are striated longitudinally and round- 
ed. 
This form is closely allied to both F. foliata and F. albida and I 
am not prepared to hold that more abundant material than has come 
under my notice will not prove it to be specifically identical with one 
of them. The characters relied upon in distinguishing it are the 
more flexuous compressed branches, less depressed dissepiments, the 
greater prominence of the carina, and the absence of striae in the longi- 
tudinal spaces between the zooecia apertures. 
Formation and locality: — Cuyahoga shales, thirty feet below Car- 
boniferous conglomerate at Cuyahoga Falls. 
FENESTELLA CAVERNOSA, n. sp. 
(Plate XIII, Figs. 7-7b.) 
Zoarium strongly folded, probably infundibuliform. All the 
specimens are fragmentary, the largest about 50 mm. long and 40 
mm. wide. 
Obverse: — Branches nearly straight, of moderate strength, rather 
unequal, averaging 0.41 mm. in width.; immediately after bifurcating 
the width is about 0.3 mm., and just beneath the next division about 
o. 5 mm. , the rate of increase between the two extremes being gradual. 
The bifurcation occurs at intervals varying betwen 6.0 mm. and 15.0 
mm., and not unfrequently take place simultaneously in a number of 
neighboring branches, causing a considerable variation in the num- 
ber of branches in a given space. Thus while the average number in 
10 mm. is seventeen or eighteen, as few as sixteen and as many as 
twenty-two may occur in an equal space, on certain portions of a frond. 
Carina small, often slightly sinuous, generally with faint nodes or 
swellings at rather irregular intervals. Entire surface between zooecia. 
apertures minutely porous, the, pores elongate so that they not infre- 
quently cause the surface to appear finely striated. Zooecia in two 
ranges, fourteen or fifteen in 5 mm.; apertures nearly direct, circular, 
0.09 mm. in diameter, a greater distance apart, three, occasionally 
four, opposite each fenestrule, and surrounded by a well developed 
peristome, sometimes obliquely prolonged posteriorly. In the thinner 
branches the peristomes project slightly beyond the margin of the 
branches. Dissepiments somewhat depressed, half as wide as the 
branches, expanding at each end. Fenestrules twice as long as wide. 
