174 Thirty-second Report on the State Museum. 



pores carinate, carina sharp, elevated, slightly thickened above in well-preserved 

 specimens. 



This species resembles F. Nervia (pi. xxii, figs. 1-6), but the branches are 

 straighter, giving a more rigid appearance to the frond, and so far as observed 

 the caringe are never connected by bars as in that species. 



Formation and locality. In the Lower Helderberg group, near Clarksville, 

 tf. Y. 



Fenestella (Hemitrypa) Nervia var. constricta, n. var. 



(PLATE XXII, FIGS. 11, 12.) 



This form differs from F. Nervia in the closer arrangement of branches and 

 much smaller fenestrules, but it is probably only a variety of that species. 



Fenestella (Hemitrypa) biserialis, n. sp. 



(PLATE XXII, FIGS. 13-18.) 



Bryozoum funnel-shaped, not rapidly expanding. 



Branches ten in the space of five mm. : on non-poriferous side rounded, gran- 

 xdose, not perceptibly striated ; opposite each dissepiment a node, which is fre- 

 quently strongly elevated forming a blunt spine. 



Dissepiments from one-third to two-thirds the width of the branches, seven or 

 eight in the space of five mm. ; on non-poriferous side slightly angular, on porif- 

 erous side rounded, on both sides depressed, expanding at their junction with 

 the branches ; oval or subquadrangular, nearly as wide as the branches ; length 

 •once and one-half to twice the width. 



Cell-pores in two ranges opening nearly directly upward; openings small, 

 circular, three in the space of a fenestrule, counting those opposite the dissepi- 

 ment ; distance from each other equal to or greater than their diameter ; mar- 

 gins elevated indenting the border of the fenestrule ; space between the ranges 

 of pores carinated, carina sharp, elevated about the diameter of a branch, 

 expanding above ; crests connected with each other by an extension of their 

 substance in the form of slender bars ; the bars of adjacent crests alternate with 

 each other, forming midway between them a longitudinal ridge of a thickness 

 equal to that of the bars, and leaving a double range of small fenestrules ; 

 twenty-three bars in the space of five mm. ; top of carina rounded, obscurely 

 striated. 



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



ICHTHYORACHIS, McCoy. 



ICHTHYORACHIS NEREIS. 

 (PLATE XXII, FIGS. 19-21.) 



IcJdhyoracMs Nereis, Hall. Twenty-sixth Rep. JST Y. St. Mus. Nat. Hist., p. 98. 1874. 



Bryozoum plumose, midrib flattened on non-poriferous side, longitudinally 

 striate with a groove along the center ; lateral branches slender, distance from 



