80 Forty-fourth Report on the State Museum, 



the cell apertures are a little smaller, and the nodes on the peris- 

 tomes and longitudinal striae are much finer, the striations are 

 fewer in number and a transverse section of the branch is more 

 nearly oval. The appearance of the frond and manner of growth 

 is very similar to that of S. rliomhoidea of the Upper Helderberg, 

 but the cell apertures are very different ; in that species they are 

 much smaller, and the peristomes are very thin and scarcely 

 elevated, the longitudinal striations are continuous, sinuous or 

 zigzag, usually coalescing between the cell apertures and inclosing 

 a rhomboidal vestibular area ; from S. interstriata this species may 

 be distinguished by the stronger peristomes, absence of spiniform 

 projections from the interior of the cell wall, the much fewer and 

 stronger longitudinal striations, and the granules of the peristomes 

 and striations ; from S. permarginata by the longitudinal stria- 

 tions, that species having the interapertural space smooth. 



Formation and locality. — Hamilton group, Darien Centre, N. Y. 



Stictopora permarginata. 



Stictopora permarginata, Hall. Trans. Albany Institute, vol. x, p. 191, 1851. 



Eeport of State Geologist for 1883, p. 46, 

 1884. 

 " '• " Palaeontology of New York, vol. vi, p. 258, 



pi. xiii, fig. 16, 1887. 



This species most closely resembles S, granifera, but may be 

 distinguished from that species ; the frond is narrower and more 

 rigid in appearance, the branches do not widen before bifurcating, 

 the cell apertures are somewhat larger, much more closely dis- 

 posed, the peristomes are stronger, the striations are stronger and 

 much more infrequent. It very closely resembles S. divergenSj 

 but may be distinguished by the wider fronds more infrequent 

 bifurcations, the parallel margins, more closely disposed cell 

 apertures and the stronger nodes on the peristomes and striations. 



Formation and locality. — Hamilton group, West Hamburg, Erie 

 county, N, Y. 



