

172 NEW YORK STATE MUSEUM 



Genus polypora McCoy 



[Ety.: izoibq, many; ■Kopo<s, pore] 



(1845. Synopsis Carbon, foss. Ireland, p. 206) 



Zoarium as in F e n e s t e 1 1 a , but with from two to eight rows 

 of zooecia on a branch, and without median keel, but sometimes 

 with a row of strong nodes or tubercles. 



Polypora incepta Hall (Fig. j$) (1852. Pal. N. Y. 2:167, pi- 

 40D, fig. 5a-f) 



. ..-=».. ___ Distinguishing characters. 



itejsju 1 Funnel-shaped, but generally 



■'.'/' 1- * 4 % compressed form; branches 



**' t t M dividing somewhat regularly, 



sometimes anastomosing; dis- 

 sepiments at regular intervals, 

 slender, scarcely thickened at 

 their junction with branches;, 

 fenestrules oblong, quadran- 

 gular, rarely oval; non-celluli- 

 ferous face longitudinally 

 striate; three or four rows of 

 cell apertures, oval and alter- 

 nating; dissepiments thinner 

 on celluliferous than on non- 

 celluliferous face; sometimes 

 expanding at the junction 

 with the branches; non-eel- 

 luliferous face indistinguish- 



Fig. 73 Polypora incepta with non-eelluliferous and . . 



celluliferous faces enlarged able from t enesteila. 



Found abundantly in the Bryozoa beds of the Rochester shale at 

 Niagara, and the talus of the cliff above Lewiston hights. Also in. 

 the shale at Lockport (Hall). 



Genus helopora Hall 



[Ety.; -/J/09, nail; nopos, pore] 



(1852. Pal. N. Y. 2:44) 



Zoarium bushy, dichotomously branching, the whole consisting- 

 of numerous slender, equal segments, united by terminal articula- 





'],! 



