120 
PALEONTOLOGY OF NEW YORK. 
Fenestella (Reteporina) rhombifera 
PLATE L, FIGS. 18, 19. 
Fenestella rhombifera, Hall. Trans. Albany Institute, vol. x, abstract, p. 32. 1881. 
“ “ “ Report of State Geologist for 1385, advance sheets. Expl. pi. 50, tigs. 18, 
19. 1S86. 
Compare Fenestella striata. Thirty-sixth Annual Rept. N. Y. State Mus. Nat. Hist., extract, p. 72. 1884. 
Bryozoum 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; carime 
strong, height .40 mm. 
The non-celluliferous face of this species so nearly resembles that of F. 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. 
NOT FIGURED. 
Bryozoum infundibuliform. Branches moderately slender, very gradually en¬ 
larging, width above a bifurcation .30 mm., increasing to .45 mm., angular, 
