46 
PALEONTOLOGY OF NEW-YORK. 
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, b. 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 PHiENOPORA( nov. gen.). 
[Gr. (paivw, fenestro ; and iropoi, pones.) 
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. PMNOPORA EXPLANATA (n. sp.). 
Pl. XVIII. Fig. 6 a-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. 
