CORALS AND BRYOZOA. 113 



b. Forms having a smooth carina. 

 Fenestella biseriata, n. sp. 



PLATE XLII, FIGS. 16-18. 



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

 cation .35 mm., increasing to .50 mm.; very gradually enlarging, straight, 

 somewhat rigid in appearance, rounded or sub-angular, finel}^ striated, occa- 

 sionally with minute nodes ; bifurcations distant. Interstices wider than the 

 branches, sometimes twice the width. Dissepiments very slender, width .22 

 mm., rounded or sub-angular, sometimes slightly carinated, nearly on a plane 

 with the branches, five in the space of 5.50 mm. Fenestrules sub-quad- 

 rangular or oval, length nearly .80 mm., width usually about .50 mm. 



On the celluliferous face the branches are angular. Dissepiments rounded 

 or sub-angular, very much depressed. Fenestrules a little narrower than on 

 the opposite face. Cell apertures in two ranges, opening somewhat laterally, 

 twenty in the space of 5 mm., separated by the diameter of an aperture: 

 margins thin, slightly elevated. Surface between ranges of apertures angular, 

 8ub-carinated. 



Formation and locality. Upper Helderberg group. Cherry Valley, Otsego 

 county, N. Y. 



Fenestella peculiaris. 



PLATE XLII, FIGS. lB-21. 

 FtnesUUa peculiaris, Hali. Report of State Geologist for 1883. Expl. pi. 33, figs. 19-21. 1883. 



BRTOzonM infundibuliform. Branches slender, very gradually enlarging ; width 

 above a bifurcation .33 mm., increasing to .40 or .45 mm. ; obtusely angular, 

 except for a .short distance before bifurcating, carinated, carina and other 

 parts of the branch nodose or granulose. When the frond is much macerated 

 the nodes are obsolete and the carina is much more prominent than in well- 

 preserved specimens. Interstices a little wider than the branches. Dissepi- 

 ments slender, width .30 mm., flattened, granulose, slightly depressed, five 

 in the space of 5 mm. Fenestrules oval, length .70 mm., width .35 to 

 .40 mm. 



