80 
PALEONTOLOGY OF NEW YORK. 
oblique than the others; the posterior or upper portions of the walls are 
exposed for nearly their entire length, being more or less distinctly carinate. 
There are slightly elevated, transverse ridges between the larger cells, giving 
to the maculae a geometrical appearance. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Lichenalia ovata. 
PLATE XXXII, FIGS. 1-5. 
Lichenalia ovata, Hall. Report of State Geologist for 1S85. Expl. pi. 32, figs. 1-5. 1887. 
Zoarium consisting of lamellate expansions, free or encrusting. Thickness of 
specimens observed 2 mm. Cells tubular, cylindrical, at right angles to the 
surface; septa wanting. Apertures broadly ovate and sometimes trilobate, 
length .40 mm., width three-fourths the length; radiating from maculae. 
Posterior margin of peristomes strongly elevated, oblique, frequently with two 
slight denticulations. Surface with substellate maculae destitute of cell aper¬ 
tures, the centers of which are distant from each other about 5 mm., diame¬ 
ter 2 mm.; adjacent apertures not larger than the others. Intercellular 
space regularly septate, septa distant. 
This species closely resembles L. substellata, but may be distinguished by its 
larger, more ovate cell apertures, and the absence of septa in the cell tubes; 
from Lichenalia ( Odontotrypa ) alveola by its less closely arranged, ovate cell aper¬ 
tures, well defined apertural margins, and its thicker fronds. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Lichenalia alternata. 
PLATE XXXI, FIGS. 39-41. 
Lichenalia alternata. Hall. Trans. Albany Institute, vol. x, abstract, p. 8. 1881. 
“ “ “ Report of State Geologist for 1885. Expl. pi. 31, figs. 39-41. 1887. 
Zoarium consisting of very thin lamellate expansions, incrusting other objects. 
Cell apertures oval, length about .35 mm., width from one-half to two-thirds 
the length; closely disposed, frequently alternating and sub-imbricating. Pos- 
