i 



86 Forty- FOURTH Report on the State Museum. 



Hederella conferta. • 



Ptilionella conferta, Hall. Trans. Albany Institute, vol. x, p. 195, 1881. 



" Eeport of State Geologist for 1883, p. 56, 1884. 

 " " ** Palaeontology of New York, vol. vi, p. 279, not 



figured, 1887. 



This species may be distinguished from Beptaria penniformis 

 by the different appearance of the axial tube, the greater diame- 

 ter of the cell tubes, their more nearly cylindrical form, and the 

 absence of regular annulations ; from Ptilionella nodata it is easily 

 distinguished by the absence of prominent regular annulations ; 

 from Hederella cirrhosa it is distinguished by the much larger cell 

 tubes, their comparatively more frequent occurrence, and the more 

 compact appearance of the frond ; from H. canadensis by the 

 larger more frequent cell tubes and the more compact appearance 

 of the frond. The cell tubes are of nearly the same size as those 

 of H. filiformiSj but they are of more frequent occurrence and are 

 never nearly parallel with, nor have their margins in contact with 

 the axial tube, but diverging and having their margins in contact 

 with each other, presenting a more compact appearance than that 

 species ; from H. magna it is distinguished by the much smaller 

 size of the cell tube. 



Formation and locality. — Hamilton group, Darien Centre, 

 Genesee county, N. Y. 



Ptilopora striata. 



Ptilopora striata, Hall. Trans. Albany Institute, vol. x, p. 196, 1881. 



Eeport of State Geologist for 1883, p. 58, 1884. 

 " " " Palaeontology of New York, vol. vi. p. 283, pi'. Ixvi, 



figs. 30-33, 1887. 



This species may be distinguished from P. tenuis by the stronger 

 midrib and the more frequent lateral branches ; in that species 

 the interval between the branches is nearly twice as great as in 

 this species ; from P. nodosa it may be distinguished by the more 

 frequent branches and - the absence of prominent nodes on the 

 celluliferous face of the midrib and branches. 



Formation and localities. — Hamilton group, Moscow, Livingston 

 county, and other localities in Central and Western New York, 

 and also at West Williams, Ontario, Canada. ^ 



