From the Niagara Formation, 



63 



branch, and on well-preserved specimens finely granulose : dissepi- 

 ments extremely slender, frequently oblique, and not expanding at 

 their junction with the branches. Fenestrules quadrangular, vary- 

 ing from equal to twice the width of the branches, length from two 

 to three times the width. Cell-pores in two ranges, apertures circu- 

 lar, four in the length of a fenestrule, opening obliquely upward : 

 distance between the cell-apertures equal to, or a little less than, their 

 diameter : margins slightly elevated. Centre of the branch longitu- 

 dinally carinated ; carina sharp and slightly elevated. 



Fenestella bellastriata n. sp. 



Frond funnel-shaped, branches strong, rigid, very gradually en- 

 larging to the bifurcation. Surface of non-poriferous side flattened, 

 strongly striated, striae two to three upon each branch except just 

 below the bifurcation where the number is greater : dissepiments 

 from one-half to two-thirds the width of the branches, expanded at 

 their junction, about six in the space of five mm. Fenestrules elon- 

 gate-oval, width about equal to that of the branches, length two or 

 three times the width : cell-pores in two ranges, three in the length 

 of each fenestrule, opening laterally, and slightly upward ; margins 

 elevated and indenting the border of the fenestrule. Centre of the 

 branch carinated, carina narrow and little elevated. 



This species differs from F. pertenuis, in its stronger branches and 

 much wider dissepiments, which are expanded at their junction with 

 the branches, in the elongate-oval fenestrules, the strong sharp 

 • striseon the non-poriferous side, and in the number of pores in the 

 length of a fenestrule. 



Fenestella coxeerta n. sp. 



Frond flabelliform, branches slender, about seven in the space of 

 five mm. ; non-poriferous side rounded, striated; strife granulose, four 

 or five on the width of the branch ; bifurcations very frequent and ir- 

 regular : dissepiments, from one-third to one-half the width of the 

 branches, widening at their junction, usually direct but sometimes 

 oblique, three in the space of five mm. Fenestrules subquadrangu- 

 lar, varying from equal to nearly double the width of the branches, 

 length about three times the width. Cell-pores in from two to four 

 ranges, usually three ranges ; six to seven in the space of each fenes- 

 trule. 



