Report of the State Geologist. 79 



tinguished by the peculiar mode of branching, and in having the 

 non-cellnliferous margin bordering the entire frond. 



Formatidn and localities. — Shales of the Hamilton group, West 

 Hamburg, Erie county ; Pavilion, Genesee county, and near 

 Canandaigua lake, Ontario county, N. T. 



Stictopora granifera. 



Stictopora granifera, Hall. Trans. Albany Institute, vol. x, p. 191, 1881. 



Report of State Geologist for 1883, p. 45, 1884. 

 ** '• " Palaeontology of New York, vol. vi, p. 257, pi. 



Ixi, figs. 1-6, 1887. 



■X- -X- * ^4f * ^ * * 



This species may be distinguished from S. interstriata by the 

 difference in manner of growth, the branches being much widened 

 before bifurcating, while in that species the margins of the frond 

 are parallel, the peristomes and interapertural strise are nearly 

 equal in strength and are granulose ; the cell apertures are very 

 indistinct, while in ;S^. interstriata they are conspicuous ; when a 

 frond of this species is weathered so that the granules are nearly 

 or quite obsolete the resemblance to that species is much greater. 

 From S. divergens it may be distinguished by the size of the 

 frond, the width of that species being only from 1 to 1.50 mm., 

 the comparatively greater expansion before bifurcating, the larger 

 cell apertures and the somewhat more numerous striations ; from 

 8. sinuosa it may be distinguished by the great expansion of the 

 branches before bifurcating, the more lax appearance of the frond, 

 the more elongate oval apertures, more numerous and straighter 

 striations, and the granules on the peristomes and striae. 



Formation and localities. — Hamilton group, near Pavilion 

 village, Genesee county, and Muttonville, North Bristol township, 

 Ontario county, N. Y. 



Stictopora diYergens. 



stictopora divergens, Hall. Palaeontology of New York, vol. vi, p. 257, 



pl. Ixiii, figs. 18, 19, 1887. 



This species most closely resembles S. granifera, but the fronds 

 are narrower, the margins of the branches are more nearly parallel, 

 and the branches increase but little in width before bifurcating ; 



