46 



PALEONTOLOGY OF NEW-YOEK. 



425. 8. STICTOPORA RARIPORA (n. sp.). 



Pl. XVIII. Fig. 5 a, b, c. 



Stipe slender, divaricately bifurcating or alternately branching ; surface of stipe and branches 

 marked by about three rows of oval cells ; cells distant, with an elevated margin ; surface of 

 stipe apparently striated. 



This slender species is readily recognized by the few and widely separated cellules. The 

 stipe is also more nearly cylindrical, and has apparently no extended non-celluliferous margins. 



Fig. 5 a, h. Two specimens of this species. 

 Fig. 5 c. A portion enlarged. 



Position and locality. In the thin calcareous layers of this group at Flamborough head, 

 Canada West. The same species occurs in the shale of the Niagara group at Rochester, N. Y. 



Genus P H^NOP OR A (nov. g-en.). 

 [Gr. (paivu, fenestra ; and ■ropo?, 'porus.^ 

 Corallum consisting of a thin broad calcareous or semi-calcareous expansion, which is cellu- 

 liferous on both sides ; cellules oval, arranged between direct longitudinal and obliquely trans- 

 verse lamellae, and opening upward and outwards from the base. 



The specimens of this genus have a near resemblance to the species of Fenestella, with 

 small fenestrules ; but this resemblance is only apparent, and more especially observable in 

 worn specimens. The cells have not always the ascending or spiral arrangement noticed in 

 Stictopora ; and there is no smooth or striated margin destitute of cells, as in that genus. 



426. 1. PHiENOPORA EXPLANATA {n. sp.). 



Pl. XVIII. Fig. 6a-e. 



Corallum consisting of a thin, even, expanded crust with no apparent tendency to branching, 

 both sides equally celluliferous ; cellules minute, oval, arranged between thin longitudinal 

 lamellae ; transverse arrangement of cellules obliquely ascending and separated by a sharp 

 elevated line, sometimes somewhat irregularly arching or undulating. 



Cellules in the transverse direction, 8 in the space of one line ; in the longitudinal direction, 

 10 to 11 in the same space. 



This species, particularly when a little worn, bears a close resemblance to the non-poriferous 

 side of a Fenestella with minute openings, and the true form of the little cellules is not per- 

 ceptible to the naked eye. The bases of the cells, from the two sides, are separated by a thin 

 calcareous membrane. The longitudinal laminae, separating the rows of cells, are coincident 

 on the two sides. 



