164 Thirty-second Report on the State Museum. 



cell-margins elevated, and indenting the borders of the fenestrule ; space 

 between ranges of pores strongly striated on well-preserved specimens. 

 Formation and locality. Lower Helderberg group, Clarksville, N. Y. 



Fenestella paxillata, n. sp. 



(PLATE XVIII, FIGS. 10-12.) 



Bryozoum flabellate or funnel-shaped. Branches, compared with the size of 

 frond, slender; five or six in the space of five mm. ; bifurcations distant; 

 branches on non-poriferous side flattened, striated ; striae fine, from four to seven 

 on a branch ; for a short distance below the bifurcation is a broad, shallow, 

 groove, extending less distinctly and narrower nearly the whole length of the 

 branch. 



Dissepiments four in the space of six mm. ; width about two-thirds that of 

 the branches, rapidly expanding at their junction with the branches ; on non- 

 poriferous side they are on the same plane as the branches ; on poriferous side 

 depressed. 



Fenestrules oval to subquadrangular ; a little more than twice as long as 

 wide ; width slightly more than that of the branches. 



Cell-pores in three ranges, except for the distance of about two fenestrules 

 below the bifurcations, where there are four in this space; the two central 

 ranges are very close together and alternating, and open directly upward ; the 

 ranges on the sides are distant from the central range or ranges, and open so 

 directly outward that, in looking perpendicularly upon the specimen, they are 

 scarcely visible ; margin of cells but very little elevated ; six in the space of a 

 fenestrule. 



On account of the distant bifurcations, the branches run directly parallel for 

 some distance, without increasing in size, which gives to the frond a peculiarly 

 rigid appearance, distinguishing it from any other species. 



Formation and locality. Lower Helderberg group, near Clarksville, N. Y. 



Fenestella compressa, n. sp. 



(PLATE XVIII, FIGS. 11-18.) 



Bryozoum funnel-shaped. Branches, five in the space of five mm., much en- 

 larged near the frequent and irregular bifurcations ; on the non-poriferous side 

 branches round, with fine but distinct striae, which are frequently finely granu- 

 lose ; five or six on a branch. 



Dissepiments about one-half as wide as the branches, granulose -striate, slightly 

 expanding at their junction with the branches, occurring at irregular intervals, 

 averaging about four in the space of five mm. 



Fenestrules very variable in shape, from elongate-ovate to broadly oval or 

 subquadrangular; width about one and one-half greater than that of the 

 branches ; length from two to three times the width. 



