180 PALEONTOLOGY OF NEW YORK. 



Fenestella perplexa. 



MOT FIGDIIKD. 



Pneildki (HanUrypa) perplexa. Hall. Trans. Albany Institute, vol. x, abstract, p. 33. 1881. 

 " blgeneris, Ulkioh. Cont. Am. Pal., vol. i. No. 1, p. 11, pi. 2, figs. 1, la. 



Bbyozoum infundibuliform. Branches slender, width above a bifurcation usually 

 from .20 to .25 mm., increasing to .35 or .40 mm., usually straight, some- 

 times irregular, rounded, nodose ; nodes small, irregularly disposed; transverse 

 section of branch cuneiform, width .25 to .40 mm., depth 1.25 mm. Inter- 

 stices of about the same width as the branches. Dissepiments slender, width 

 .25 mm., depth 1 mm., rounded, on a plane with the branches or elevated 

 above, sometimes continuing across the branch and coalescing with adjacent 

 dissepiments, forming very irregular transverse ridges, seven in the space 

 of 5 mm. Fenestrules oval, length .45 mm., width about .25 mm. 



On the celluliferous face the dissepiments are angular, carinated, the carin£B 

 extending upon the branch and to the summit of the carina of the branch. 

 Fenestrules narrower than on the opposite face. Cell apertures in two ran- 

 ges, opening laterally, twenty in the space of 5 mm., separated by less than 

 the diameter of an aperture. Branches carinated; carinae thin, height. 25 mm., 

 and having, on the summit, a row of irregular nodes, which extend beyond 

 the carinae and have precisely the appearance as if they had been originally 

 extended and connected adjacent carinae forming scalse, which had been 

 broken away, leaving only the attached portions ; twenty in the space of 

 5 mm. . 



This species may be very easily distinguished, by the peculiar appearance of 

 the summit of the carina. 



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



