50 PALMONTOLOGY OF NEW YORK. 



On the celluliferous face the branches are angular and the dissepiments 

 much depressed. The fenestrules appear somewhat narrower and more reg- 

 ular than on the opposite face. Cell apertures small, circular, three in the 

 length of a fenestrule, disposed in two ranges, opening laterally at an angle 

 of forty-five degrees to the axis of the branch : margins elevated, slightly 

 indenting the borders of the fenestrules. Between the ranges of apertures 

 there is a line of nodes along the summit of the branch. 



Width of branches at first .25 mm., increasing to .75 mm. Diameter of 

 dissepiments from .16 to .18 mm. ; length of fenestrules from .40 to .50 mm. 



Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 



Fenestella Philia. 



plate xx, figs 9-11. 



FfnesUlla Philia. Hall. Thirty-second Rept. N. Y. SUte Mus. Nat. Hist., p. 168. 1879. 



Report of State Geologist for 1882. Expl. pi. 20, figs. 9-11. 1883. 



Bryozoum probably infundibuliform, and radially plicate. Branches slender, 

 rounded and smooth, from twelve to sixteen in the space of 5 mm. Dissepi- 

 ments slender, nine in the space of 5 mm. Interstices usually wider than 

 the branches. Fenestrules sub-quadrangular. 



On the celluliferous fiice the branches are angular and marked by a line of 

 nodes along the center. Cell apertures in two ranges, small, circular or sub- 

 oval, three in the space of one fenestrule, distant from each other more than 

 the diameter of an aperture. 



Formation and locality. In the shaly limestone of the Lower Helderberg 

 group, near Clarksville, N. Y. 



Fenestella Thyene. 



PLATE XXI, FIGS. 1-5. 



PenetteUa Thyene, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 170. 1879. 

 FmateUa Thyene, Hall. Report of SUte Geologist for 1882. Expl. pi. 21, figs. 1-5. 1883. 



Bryozoum infundibuliform, growing directly from a spreading base without a 

 pedicel. Branches moderately strong, angular, corapcactly arranged, straight 



