CORALS AND BRYOZOA. 
21 
CALLOPORA, Hall. 1852. 
Callopora oppleta, n. sp. 
PLATE XI, FIGS. 23, 24. 
In part Callopora macropom, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 152. 18S0. 
“ Callopora macropora, “ Report of State Geologist for 18S2. Expl. pi. 11, figs. 28-29. 1883. 
Zoarium ramose, solid, diameter of branches 3 mm.; bifurcations frequent. 
Cell apertures circular, diameter .33 mm., irregularly disposed, frequently in 
contact: margins strong, equally elevated. Mesopores minute, not more than 
one series between adjacent apertures. 
Formation and locality. Lower Helderberg group, near Clarksville, Albany 
county, N. Y. 
Callopora cellulosa. 
PLATE XII, FIGS. 1-9; PLATE XIII, FIG. 9; AND PLATE XXIII A, FIG. 6. 
Callopora cellulosa, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 154. 1879. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 12, tigs. 7-9 ; pi. 13, fig. 9. 18S3. 
Zoarium ramose, solid, diameter of branches from 3 to 5 mm.; bifurcations 
frequent. Cells tubular, often sub-polygonal from mutual pressure ; arising 
from the center of the branch, gradually diverging till within one mm. of the 
surface, when they turn abruptly outward; walls, except near the surface, 
very thin. Septa thin, distant. Apertures circular or broadly oval, diameter 
from .20 to .25 mm. ; irregularly disposed, frequently in contact: margins 
strong, distinctly and equally elevated. Mesopores minute, angular: margins 
of the same height as those of the apertures. Intercellular space septate for 
a short distance below the surface. 
The surface of this species is variable in appearance ; very frequently the 
margins of the apertures and mesopores are smooth ; at other times the 
margins of the apertures have comparatively strong nodes, the mesopores 
being nearly or quite obscured ; in others the margins of both the apertures 
and mesopores are ornamented with minute spines, which often are so 
numerous as to entirely obscure all other features of the surface. 
