Report of the State Geologist, 77 



Stiatopora recta. 



Stictopora recta, Hall. Palaeontology of New York, vol. vi, p. 253. 



Not figured, 1887. 



This species most closely resembles S. hifurcata, but may be 

 distinguished by the much less frequent bifurcations, the parallel 

 margins of the branches, the less variation in size between the 

 marginal and ordinary apertures, less prominent and more irregu- 

 larly disposed granules on the longitudinal ridges ; from S. palmi- 

 pes by the different mode of growth, the absence of lateral 

 branches, narrow non-celluliferous marginal space, smaller cell 

 apertures, and less prominent longitudinal ridges ; from S. 

 angularis it may be distinguished by the somewhat narrower, 

 more regularly convex frond, smaller, more decidedly oval cell 

 apertures, which are not pustuliform, and the narrower, granu- 

 lose ridges. The cell apertures of S. angularis are circular and 

 pustuliform, and the longitudinal ridges are smooth ; nearly the 

 same features will distinguish it from S. suhrigida; from S. 

 incisurata, it may be distinguished by its narrower, more rigid 

 frond, smaller and more closely disposed cell apertures, and com- 

 paratively more prominent longitudinal, granulose ridges ; from 

 S. trilineata and S. tumulosa by the narrower frond, and promi- 

 nent, longitudinal ridges ; from Ptilodictya parallela by the dif- 

 ferent mode of growth, narrower form, smaller cell apertures and 

 more prominent ridges ; from S. rigida and >S^. crescens of the 

 Upper Helderberg group it is distinguished by the narrower 

 frond, smaller cell apertures and comparatively more prominent 

 Jiongitudinal ridges. 



Formation and locality. Hamilton group. West Hamburg, Erie 

 county, N. Y. 



Stictopora bifurcata. 



stictopora bifurcata. Hall. Palseontology of New York^ vol. vi, p. 254, pi. 



Ixiii. fig. 17, 1887. 



* * * ^ ** -jf -se-'-jf 



This species most closely resembles S. joalmipes, but may be dis. 

 tinguished by the more nearly parallel margins of the frond, the 

 absence of lateral branches, the smaller cell apertures, the some- 

 what more slender, longitudinal ridges and the less prominent 



