CORALS AND BRYOZOA. 119 



This species most nearly resembles F. (Reteporina) rhombifera and F. granifera ; 

 from the first it may be distinguished as follows : the branches are not so 

 decidedly anastomosing, the dissepiments are narrower and more closely dis- 

 posed, there being eight in the same space occupied by five in that species; from 

 F. granifera, by the branches being generally more angular, with small conical 

 nodes, and without the line of granules along the middle of the branch, charac- 

 teristic of that species ; the carina does not expand, is slightly elevated and has 

 no nodes on the sides. 



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



Fenestella cdltrata. 



PLATE L, FIGS. 1-5. 



Fenestella cuUrata, Hall. Trans. Albany Institute, vol. x, abstract, p. 29. 1881. 



" " " Report of State Geologist for 1885, advance sheets. Expl. pi. 50, figs. 



1-5. 1886. 



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

 cation .35 mm., increasing to .75 mm., rounded or sub-angular, becoming 

 flattened for a short distance before bifurcation. Interstices generally wider 

 than the branches. Dissepiments slender, width from .25 to .35 mm., rounded, 

 on a plane with the branches and frequently oblique to them ; usually about 

 two in the space of 5 mm. Fenestrules sub-quadrangular, length from 1.75 

 to 2.25 mm., width from .40 to .80 mm. 



On the celluliferous face the dissepiments are rounded, much depressed. 

 Fenestrules of the same appearance as on the opposite face. Cell apertures 

 in two ranges, opening laterally, eighteen in the space of 5 mm., closely dis- 

 posed, frequently in contact. Surface between ranges of apertures carinated ; 

 carinae strong, angular, height .30 mm. 



This species most nearly resembles F. biserrulata, but is more lax in appear- 

 ance, the fenestrules are larger, the cell apertures open laterally, and the carina 

 does not expand and has no nodes on the side. 



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



