NIAGARA FALLS AND VICINITY 169 



Phylloporina asperato-striata (Hall) (Fig. 68). Retepora 

 asperato-striata Hall (1852. Pal. A r . Y. 2:161, pi. 40C, 

 fig. 2a-h) 



Distinguishing characters. Network of anastomosing branches, 

 with oval interstices which are somewhat unequal; outer face 

 roughly striate; inner face poriferous; three, four or more rows of 

 oval or subangular cells arranged somewhat in oblique parallel lines 

 or in quincunx order; apertures in perfect specimens probably with 

 peristomes. 



Found abundantly in the Bryozoa beds of the Rochester shale at 

 Niagara. Generally adhering to the shale laminae by the cellulifer- 

 ous face. Also at Lockport (Hall). 



Genus drymotrypa Ulrich 

 [Ety. : dpu/j.6?, coppice; rpu-a, perforation] 



(1890. Gcol. sur. Illinois. 8 1399) 



Zoarium branching dichotomously at frequent intervals; zooecia 

 in several ranges, tubular, opening on one side only and springing 

 from a thin double plate, beneath which a number of vesicles are 



■xrrrm 

 ■ 





j 



Fig. C9 Drymotrypa diffusa with eelluliferous and non-celluliferous side3 enlarged 



present; reverse side longitudinally striated; vestibules expanding 

 from the orifices to the angular apertures. 



Drymotrypa diffusa (Hall) (Fig. 69) Retepora diffusa 

 Hall (1852. Pal. N. Y. 2 :i6o, pi. 40C, fig. ia-f) 



Distinguishing characters. Shrubby form, several stems originat- 

 ing from a common base; stems frequently bifurcating and spread- 

 ing laterally, forming a broad frond; stems and branches cellulifer- 



