CLINTON GROUP. 



47 



Worn specimens of Stictopoha present a near resemblance to this and other species ; but 

 the laminffl separating the cells are never so directly longitudinal, but more or less undulating, 

 corresponding to the alternating arrangement of the cellules. By a careful examination, even 

 small worn fragments of the two genera, often met with in the same fragment of stone, may 

 be easily distinguished. In unworn specimens of this species, the longitudinal lamellae are 

 distinctly crossed by a sharp elevated line, dividing the surface into rhomboidal spaces cor- 

 responding with the cellules. 



Fig. 6 a. A small unworn fragment, of the natural size. 



Fig. 6 J. A similar fragment with the surface somewhat abraded. 



Fig. 6 c, d. The two last, respectively, enlarged, showing the difference between the worn and 



unworn surface. 

 Fig 6 e. A portion still farther enlarged, showing the form of the openings of the cellules. 



Position and locality. In the thin layers of limestone alternating with shale at Flamborough 

 head, Canada West. Probably also at Lockport and other places in New- York, but not col- 

 lected at these localities. 



427. 2. PH^NOPORA CONSTELLATA(n. 5j9.). 



PL. XVIII. Fig. 7 a, b, c, d, e. 



Corallum broadly expanded and elongated, with the two edges parallel ; both sides cellulife- 

 rous ; cellules minute, oval, arranged between thin longitudinal lamellae which separate the rows, 

 transversely arranged in nearly a direct or slightly undulating line ; surface of the crust marked 

 at regular intervals by circular depressions, in the centre of which is a point more elevated than 

 the general surface. 



This species resembles the last in some degree ; and being preserved in the iron ore, it is 

 difficult to point out the differences in the more minute details. The most obvious distinction 

 exists in the circular impressions, which are regularly arranged in obliquely transverse lines 

 over the surface. The space between the bases of the cells is much vrider than in the last 

 species. 



Fig. 7 a. A portion of a large specimen, showing the entire width of the stipe. The specimen 

 shows only the bases of the cellules, the upper portion with the centre having been 

 broken away. 



Fig. 7 b. A. fragment presenting casts of the cellules, the calcareous matter being removed. 



Fig. 7 c. A surface showing the bases of the cellules at their origin. 



Fig. 7 d. A portion of 7 a enlarged. 



Fig. 7 e. A portion of surface of 7 J enlarged. 



Position and locality. In the iron ore of WajTie county, central part of the group ; also at 

 RejTiale's basin, Niagara county. 



