Report of the State Geologist.' 71 



cell apertures, the greater mimber of ranges of cell apertures, the 

 striated convex space between the ranges of apertures, and the 

 smooth noncelluliferous marginal space ; from S. rigida it may be 

 distinguished by the wider branches, greater number of ranges of 

 apertures, the smaller, more distant and more decidedly oval cell 

 apertures, and the broader, convex space between the ranges 

 of apertures ; in that species the ranges of apertures are sepa- 

 rated by strong angular, striated ridges, not wider than the cell 

 apertures ; from S. crenulata it may be distinguished by its wider, 

 more rigid branches, greater number of ranges of oval apertures, 

 and convex interspace ; from S. suhrigida and S. angularis, by its 

 wider branches, oval, not pustulose cell apertures, and the 

 absence of strong ridges separating the ranges of apertures ; 

 from S. recta by the wider frond, greater number of ranges of 

 apertures, and the absence of strong longitudinal, granulose 

 I'idges ; from S. incisurata, by the parallel margins of the frond 

 and ranges of apertures, the smaller apertures and the convex, 

 striated interapertural space ; from S. trilineata and S. tumulosa 

 by the greater number of ranges of smaller apertures and the 

 convex or subangular, finely striated interspaces. 



Formation and locality. — Hamilton group. West Williams, Onta- 

 rio, Canada. 



Stictopora tumulosa. 



Stictopora tumulosa, Hall. Palaeontology of New York, vol. vi, p. 246, pi. 



1x1, figs. 18-22, 1887. 



This species in its general appearance and mode of branching 

 most nearly resembles S. trilineata^ but the frond is thinner, more 

 flattened ; the apertures are smaller, more decidedly circular, 

 pustuliform, more distant ; the striations are fewer and less prom- 

 inent ; from S. incisurata it may be distinguished by the parallel 

 margins of the frond, smaller, circular, pustuliform and more 

 distant cell apertures, the finer, more numerous striations ; from 

 S. sinuosa it may be distinguished by its somewhat wider 

 branches, smaller, circular, more distant cell apertures, finer and 

 generally continuous striations. S. angularis and S. recta have 

 circular, pustuliform cell apertures, but in those species the 

 ranges of apertures are separated by very prominent, strong 



