120 PALEONTOLOGY OF NEW YORK. 



Fenestella (Reteporina) rhombifeba. 



PLATE L, FIGS. 18, 19. 



Finettdla rhotnbifera. Hall. Trans. Albany Institute, vol. x, abstract, p. 32. 1S81. 



" " " Report of State Geologist for 1S85, advance sheets. Expl. pi. 50, figs. 18, 



19. 1S86. 

 Compare JFhiestella striata. Thirty-sixth Annual Rept. N. Y. State Mus. Nat. Hist., extract, p. 72. 1884. 



Bbyozoum infundibuliform, rapidly expanding, sometimes having a diameter of 

 80 mm. at 30 mm. from the base. Branches moderately slender, width 

 above a bifurcation .35 mm., increasing to .45 or .50 mm., very gradually 

 enlarging, zig-zag, anastomosing, angular, slightly carinated, with a conical 

 node at the junction, the frond presenting a regular reticulated appearance. 

 Interstices much wider than the branches. The anastomosed portions have 

 a width of .70 or .80 mm. ; three in the space of 5.50 mm. 



On the celluliferous face the branches are straight or a little sinuous, con- 

 nected by short dissepiments, which are rounded and much depressed. Fenes- 

 trules narrower than on the opposite face, width a little less than .50 mm. 

 Cell .apertures in two ranges, opening laterally, fourteen in the space of 5 

 mm., separated by more than the diameter of an aperture : margins thin, 

 slightly elevated. Surface between ranges of apertures carinated ; carinae 

 strong, height .40 mm. 



The non-celluliferous face of this species so nearly resembles that of i^. striata 

 of the Hamilton group, that no satisfactory distinction can be made. On the 

 celluliferous face the branches are more nearly straight, and rigid in appear- 

 ance, the carina is much stronger and higher, the fenestrules are larger, the cell 

 apertures open laterally, are farther apart, there being only fourteen in the 

 same space occupied by twenty or twenty-two in that species. 



Formation and locality. Upper Helderberg group, Ontario, Canada. 



Fenestella (Reteporina) coalescens. 



HOT FiaURBD. 



Bryozoum infundibuliform. Branches moderately slender, very gradually en- 

 larging, width above a bifurcation .30 mm., increasing to .45 mm., angular, 



