CORALS AND BRYOZOA. 169 



Fenestella (Polypora) l^vinodata. 



PLATE XLII, FIGS. 12-15. 



Feneatdla lemnodaia. Hail. Trans. Albany Institute, vol. x, abstract, p. 28. 1881. 



" (Polypora) Imvirutdata, Hall. Report of State Geologist for 1885, advance sheets. Expl. pi. 33, 



figs. 12-15. 1883. 



Bryozoum infundibuliform. Branches moderately slender, width above a bifur- 

 cation .35 mm., increasing to .50 mm., straight or sinuous, angular, with a 

 very slight carina. Interstices wider than the branches. Dissepiments 

 strong, width .50 mm. or more, angular, carinated, on a plane with the 

 branches, six or seven in the space of 5 mm. Fenestrules oval, length 1.20 

 mm., width .60 mm. or slightly more. 



On the celluliferous face the branches are rounded. Dissepiments very 

 short, width .65 to .70 mm., depressed. Fenestrules smaller than on the 

 opposite face. Cell apertures in from three to five ranges, twenty in the 

 space of 5 mm., distant less than the diameter of an aperture. Ranges 

 of apertures separated by slightly elevated ridges. 



Formation and locality. Upper Helderberg group, Falls of the Ohio river. 

 Fenestella (Polypora) rustica, n. sp. 



PLATB XLUI, FIGS. 10-13. 



Bryozoum infundibuliform, fronds large, irregular. Branches strong, width 

 above a bifurcation .75 mm., increasing to from 1.60 to 2 mm., sometimes 

 straight, but frequently irregular, rounded ; sometimes the surface is concave 

 immediately below a bifurcation ; on the specimens observed it is smooth ; 

 bifurcations comparatively frequent. Interstices as wide or wider than 

 the branches. Dissepiments strong, width .85 mm., rounded, very nearly on 

 a plane with the branches and frequently oblique to them, occurring at 

 irregular intervals. Fenestrules varying in shape, usually sub-quadrangular 

 or oval, often lanceolate immediately above a bifurcation, length from 2.50 

 to 4 mm., width from .75 to 1.25 mm., occasionally a little narrower. 



On the celluliferous face the branches are rounded or sub-angular. Dis- 

 sepiments rounded, sometimes slightly carinated, much depressed. Fenes- 



