196 
PALAEONTOLOGY OF NEW YORK. 
by its somewhat more numerous and prominent monticules, the more pronounced 
depression at the center, the closer disposition of the cell apertures, the 
absence of inter-apertural pits or vesicles, and the very few opercula: from 
F. variapora , to which it bears a close general resemblance, by the depression 
at the center of the monticules, the oblique cell apertures, and absence of 
mesopores: from F. umbilicata by the less pronounced depression at the center 
of the monticules, the oblique cell apertures and absence of mesopores: from 
F. serrulata and F. confertipora by the depression in the monticules, the oblique 
cell apertures and absence of mesopores. 
Formation and locality. Hamilton group, West Bloomfield, N. Y. 
Liciienalia subtrigona, n. sp. 
NOT FIGURED. 
Zoarium consisting of free or incrusting explanate fronds, or of masses formed 
by the accretion of successive layers of growth ; under surface a thin epitheca 
with strong concentric wrinkles or undulations, frequently irregular or con¬ 
torted, and also with fine radiating markings, caused by the recumbent 
portions of the cells; thickness of fronds from 1 to 5 mm. Cells tubular, 
rectangular to the surface, walls thin; septa moderately frequent. Inter¬ 
cellular tissue vesiculose, vesicles large, frequently having a diameter of 
between .30 and .40 mm., and rarely of more than .00 mm.; near the base 
they are always very irregularly disposed, and usually so for the whole depth 
of the frond, but sometimes more regularly superimposed above, but never 
having the appearance of walled, septate tubuli. Cell apertures ovate or sub- 
trilobate, length .33 mm., width three-fourths the length, irregularity dis¬ 
posed, sometimes in contact, at other times separated by more than the 
width of an aperture. Peristomes moderately thick, usually equally 
elevated, but sometimes the posterior portion is the stronger, and also shows 
faint indications of denticulations. The surface is marked by maculae, 
destitute of cell apertures, the centers of which are distant about 8 mm.; 
the adjacent apertures are larger than the others, more nearly circular, and 
have an indistinct radiation therefrom. 
