166 



PALEONTOLOGY OF NEW-YORK. 



Fig. 2 c. An enlarged view, looking into the cells from a direction oblique to the surface of the 



frond. 

 Fig. 2 d, e. Lateral and basal view of a fragment of the cup broken off just above the root : the 



thin sharp prominent edges of the branches are very distinctly seen. 

 Fig. 2 /. A specimen showing a fragment of the non-poriferous face of Polypora incepta and of 



Fenestella tenuiceps. 

 Fig. 2 ^. A portion of the latter enlarged, showing the form of fenestrules and the granular worn 



surface. 

 Fig. 2 ^. A portion of another fragment enlarged, showing the striated surface of the branches. 



Position and locality. In the shale of the Niagara group, particularly in the thin calcareous 

 layers at Lockport : more rarely at Rochester and elsewhere. 



{State Collection. Collection of Col. J e^ett.) 



660. 5. FENESTELLA CRIBROSA {n. sp.). 



Pl. XL D. Fig. 3 a, b. 



Frond expanded or cyathiform ; branches strong, irregularly bifurcating ; surface striated ; 

 transverse bars or dissepiments tliln, scarcely enlarging at their junction with the branches ; 

 fenestrules small, quadrangular, sometimes oval ; poriferous side unknown. 



Fenestrules eleven in the space of three lines longitudinally, and eighteen in the same space 

 transversely. 



This species is readily distinguished by the small angular fenestrules, which are much more 

 numerous than in the same space in any other species in this group ; the branches are quite as 

 strong, or even stronger than in F. elegans. It is easily distinguished, therefore, by the non- 

 celluliferous side alone. 



Fig. 3 (z. A fragment natural size. 



Fig. 3 i. A portion of the same magnified. 



Position and locality. In the lower part of the Niagara limestone at Lockport. 



56L 6. FENESTELLA {n. sp.). 



PL. XL D. Fig. 4. 



The base of the cup of two specimens have been found, showing much stronger branches 

 than either of the preceding. The arrangement of the fenestrules or bells has not been observed. 

 Position and locality. Shale of the Niagara group, Lockport. 



A 



