Report of the State Geologist* 75 



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Stictopora subrigida. 



Stictopora subrigida, Hall. Trans. Albany Institute, vol. x, p. 190, 1881. 



Keport of State Geologist for 1883, p. 43, 1884. 

 " *; " Palseontology of New York, vol. vi, p. 251, pi. 



Ix, fig. 21, 1887. 



This species very closely resembles S. angularis, but the bifur- 

 cations occur at much greater intervals, the longitudinal ridges 

 are much more prominent, and the cell apertures somewhat 

 smaller; it also very closely resembles S. limata, that species 

 having the bifurcations distant and the cell apertures disposed in 

 parallel rows separated by prominent ridges, whose width is 

 greater than that of the apertures, but its cell apertures are oval 

 and are separated by only a little more than the diameter of an 

 aperture ; from S. rigida of the Upper Helderberg group it is 

 distinguished by its narrower form, smaller, more decidedly circu- 

 lar and more distant cell apertures, and the broad, rounded, sepa- 

 rating ridges ; in that species it is narrower and when not worn 

 is sharply angular ; from S. crescens, by its narrower form, smaller, 

 circular cell apertures, and the broader, more prominent longi- 

 tudinal ridges ; from S. incisurata, by the narrower form, parallel 

 margiils of the branches and broad ridges separating the ranges 

 of apertures 



Formation and localities. — Hamilton group, near Middleburg, 

 Schoharie county, and railroad cutting, two and a half miles east 

 of Alden Station, Erie county, N. T. 



Stictopora crenulata. 



stictopora crenulata, Hall. Heport of State Geologist for 1883, p. 44, 1884. 

 " " Palaeontology of New York, vol. vi, p. 252, 



pi. Ix, fig. 22. 1887. 



This species in the comparatively slight, angular striations 

 between the rows of apertures resembles S. trilineata and S. tumu- 

 losa; it may be distinguished from the former by the smaller, 

 .circular cell apertures, the unequally elevated peristomes, the 

 fewer rows of apertures on a branch, the smooth non-celluliferous 

 marginal space ; from S. tumulosa it may be distinguished by the 



