48 
PALAEONTOLOGY OF NEW YORK. 
Dissepiments rounded and much depressed. The fenestrules appear larger 
and more quadrangular than on the opposite face. Cell apertures small, 
circular, in two ranges, opening laterally; twenty-five in the space of 5 mm., 
distant less than the diameter of an aperture. 
Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 
Fenestella Althaea. 
PLATE XIX, FIGS. 17-19. 
Fenestella Althea , Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 166. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 19, figs. 17-19. 1883. 
Bryozoum infundibuliform, of somewhat lax growth Branches slender, rounded, 
marked by fine strim. Bifurcations distant, frequently occurring at intervals 
of 15 mm. or more. Interstices wider than the branches. Dissepiments 
very slender, three in the space of 5 mm.; frequently oblique to the branches. 
Fenestrules quadrangular, sometimes rhomboidal from the obliquity of the 
dissepiments. 
On the celluliferous face the branches are angular and the fenestrules 
appear oval. Cell apertures circular or slightly oval, in two ranges, with 
additional apertures just below a bifurcation; about twenty in the space of 
5 mm.; distant less than half the diameter of an aperture. 
This species, in some of its features, closely resembles F. crebripora, but it is 
of much coarser growth. 
Formation and locality. Lower Helderberg group, Albany county, N. Y. 
Fenestella Adraste. 
PLATE XX, FIGS. 19-22. 
Fenestella Adraste, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 169. 1879. 
“ “ “ Report of State Geologist for 1S82. Expl. pi. 20, figs. 20-22. 1883. 
“ sp. ? “ Report of State Geologist for 1832. Expl. pi. 20, fig. 19. 18S3. 
Bryozoum infundibuliform, compact. Branches moderately strong, flat, with a 
prominent carina along the middle, and on the wider portions of the branch 
there is occasionally a striation on each side of the carina. Bifurcations 
