CORALS AND BRYOZOA. 
187 
I have hesitated to place this species in the sub-genus Orthopora on account 
of the irregular disposition of the cell apertures, but the internal structure, 
except as noted in the last sentence, is precisely the same as in undoubted 
species of that sub-genus. 
This species most nearly resembles T. (0.) transversa and T. (0.) elongata, but 
it may be distinguished from both these by the irregular disposition of the 
cell apertures; from all other species of this geological formation it is dis¬ 
tinguished by the numerous, comparatively prominent nodes on the elevated 
surface between the cell apertures. 
Formation and locality. Hamilton group, Owasco Lake, N. Y. 
Trematopora (Orthopora?) transversa. 
PLATE LV, FIG. 12; AND PLATE LVI, FIGS 13,14 
Trematopoi-a transversa, Hall. Trans. Albany Institute, vol. x, p. 180. 1881. 
“ “ “ Report of State Geologist for 1883, p. 8. 1884. 
Zoarium ramose, bifurcations infrequent, branches widely diverging, diameter 
about 1.75 mm. Cells tubular, arising from the centre of the branch, length 
1.50 mm., for the greater portion of their length in contact, gently curving, 
and abruptly turning outward near the surface; septa near the center of the 
branch wanting, in the outer portion numerous, thicker than the cell walls, 
generally extending only partially across the cavity. Cell apertures oval, 
length .22 mm., width generally about one-half the length, usually disposed 
in longitudinal rows, frequently alternating and forming oblique transverse 
rows, and sometimes irregularly disposed. Peristomes moderately strong, 
slightly elevated. Surface between the cell apertures flat or slightly con¬ 
cave, with numerous small nodes or granules, one or two series around each 
aperture. The nodes in the course of growth form minute curved tubuli 
between the cell apertures. 
This species most nearly resembles T. (0.) elongata, but may be distinguished 
by the thicker branches and more broadly oval cell apertures. The cell tubes 
are more regularly curved and the interstitial cells are more numerous, the 
septa are stronger, occur much more frequently and extend only partially 
