164 PALEONTOLOGY OF NEW YORK. 



.20 mm., angular, slightly carinated, much depressed below the plane of the 

 branches, about five in the space of 5 mm. Fenestrules oval, length about 

 .80 mm., width from .35 to .40 mm. 



On the celluliferous face the branches are rounded Dissepiments angular, 

 slightly carinated, much depressed. Fenestrules a little narrower than on 

 the opposite face. Cell apertures in two and three ranges, opening outward, 

 sixteen in the space of 5 mm., separated by less than the diameter of an 

 aperture, outer ranges slightly oblique to the axis of the branch ; margins 

 unequally elevated, the upper portion being the strongest: the apertures 

 apparently open obliquely toward the base of the frond. Ranges of apertures 

 separated by fine, slightly elevated, but very distinct ridges. 



This species has a general resemblance to F. (P.) elongata, but the branches 

 and dissepiments are smaller and more closely disposed, there being two dis- 

 sepiments in the space occupied by one in that species. 



Formation and locality. Upper Helderberg group, near Buffalo, N. Y. 



Fenestella (Polypora) gkanilinea. 



PLATE Xi-, FIGS. 20-28. 



JFmestella graniliiiea. Hall. Trans. Albany Institute, vol. x, abstract, p. 27. 1881. 



" (Polypora) granilinea, Hall. Report of State Geologist for 1885, advance sheets. Expl. pi. 40, 



figrs. 20-23. 1886. 



Bryozoum infundibuliform, fronds large, compact. Branches slender, width 

 above a bifurcation .38 mm., increasing to .55 or .60 mm., very gradually 

 enlarging, essentially parallel, angular, with a row of granules along the 

 middle resembling a carina, occasionally there are two or three lines of 

 granules below bifurcations ; bifurcations distant, usually occurring at inter- 

 vals of from 30 to 50 mm. Interstices slightly narrower than the branches. 

 Dissepiments slender, width .25 mm., rounded or angular, slightly depressed 

 below the plane of the branches, eleven in the space of 10 mm. Fenes- 

 trules oval, length .65 mm., width .40 mm. 



On the celluliferous face the branches are sub-angular. Dissepiments 

 angular, carinated, depressed. Fenestrules narrower than on the opposite 



