46 
PALAEONTOLOGY OF NEW YORK. 
creasing in size to a bifurcation; marked by from one to four sharp lines or 
striae, which are strongly nodose along their summits. Bifurcations infre¬ 
quent. Dissepiments slender, depressed. Interstices usually equal to the 
width of the branches. Fenestrules oval or sub-quadrangular, length about 
twice the width. 
On the fragment described there are from nine to eleven branches in the 
space of 5 mm. measured transversely, and seven fenestrules in the same 
space measured longitudinally. 
This species bears some resemblance to the non-celluliferous face of some 
specimens referred to F. (U.) Nervia, but may be readily distinguished by its 
more slender branches, wider interspaces and sub-quadrangular fenestrules. 
Formation and locality. In the shaly limestone of the Lower Helderberg 
group, at Schoharie, N. Y. 
FENESTELLA iEsYLE. 
PLATE XIX, FIGS. 11-13. 
Fenestella JEsyle, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 166. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 19, figs. 11-13. 1883. 
Bryozoum probably infundibuliform. Branches slender, rounded, marked by 
obscure striae. Bifurcations frequent, occurring at intervals of from 2 to 
5 mm. Width of interstices greater than that of the branches. Dissepi¬ 
ments rounded, six in the space of 5 mm., slightly expanding at their 
junction, and on the same plane with the branches. Fenestrules sub-quad¬ 
rangular, or broadly oval, width from one-half to two-thirds the length. 
Cell apertures small, circular, opening directly outward, twenty-five in the 
space of 5 mm.; disposed in two or three ranges, with sometimes an addi¬ 
tional aperture just below a bifurcation. 
Width of branch just above a bifurcation .20 mm., increasing to .50 mm.; 
width of dissepiments from .20 to .25 mm.; fenestrules .60 mm. long. 
The specimen represented by fig. 13, pi. xix, is more lax in its growth than 
the ordinary forms of this species. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
