186 
PALAEONTOLOGY OF NEW YORK. 
Trematopora (Orthopora) interplana, n. sp. 
PLATE LVI, FIG. 12. 
Zoarium ramose; branches infrequent, diameter 1 mm. Cell apertures broadly 
oval, length .18 mm., width three-fourths the length, disposed in very oblique, 
indistinct transverse rows, separated by less than the diameter of an aperture. 
Peristomes very thin, slightly elevated. Surface between the apertures flat, 
nodose, nodes comparatively prominent, one or two series between adjacent 
apertures. 
This species most nearly resembles T. (0.) transversa and T. (0.) elongata : from 
the former it is distinguished by the smaller size of the branches, and more 
broadly oval cell apertures : from the latter by the smaller size of the branches, 
the smaller, more broadly oval cell apertures, and the comparatively greater 
space between the apertures. 
Formation and locality. Hamilton group, near Canandaigua Lake, N. Y. 
Trematopora (Orthopora) granieera, n. sp. 
NOT FIGURED. 
Zoarium ramose; bifurcations infrequent, branches widely diverging, diameter 
from 1.50 to 2 mm. Cells tubular, arising from the centre of the branch, 
for the greater portion of their length very oblique to the axis, at about 
.50 mm. from the surface, abruptly bending outward, and separating from 
each other about the diameter of a cell tube; septa thin and infrequent. 
Cell apertures oval, length about .22 mm., width equal to two-thirds the length, 
generally irregularly disposed, but sometimes having an indistinct, oblique 
transverse arrangement. The surface between the cell apertures is elevated, 
with numerous small nodes, generally only one series, but sometimes two, 
between adjacent apertures. In the course of growth the nodes form 
minute tubuli, occupying the space between the cells near the surface. There 
is also a longitudinal structure, which, in a translucent section, appears as fine 
lines, bending abruptly downward at the cell tubes. 
