218 
PALAEONTOLOGY OF NEW YORK. 
what larger cell apertures, the more elevated mesopores, the more prominent 
monticules, and the greater central space, destitute of cell apertures. 
Formation and locality. Hamilton group, York, Livingston county, N. Y. 
Fistulipora interaspera, n. sp. 
NOT FIGURED. 
Zoarium consisting of explanate fronds incrusting other objects, usually Cyatho- 
phylloid corals; no masses formed by the superimposition of successive 
layers of growth have been seen; thickness of observed fronds from 
.50 to 1 mm. Cells tubular, cylindrical, rectangular to the surface; 
septa frequent. Intercellular space vesiculose, vesicles near the base large, 
irregularly disposed, a little smaller and more regularly superimposed above. 
Cell apertures trilobate, length about .25 mm., width usually about two- 
thirds the length, but sometimes equalling it, radiating from the maculse, 
forming irregular, intersecting rows, which are usually distant about the 
diameter of an aperture. Peristomes moderately thick, posterior portion 
the more strongly elevated, with two slight denticulations, which, in the 
course of growth, form two parallel ridges along the interior of the cell wall. 
Inter-apertural space flat, occupied by small angular pits, with comparatively 
prominent nodes at the angles; the nodes often almost entirely obscure the 
mesopores, the interapertural surface appearing solid, granulose, and the 
frond in this condition apparently belongs to the genus Lichenalia. Sur¬ 
face marked by low, rounded, irregularly disposed monticules, the centers of 
which are distant from each other about 5 mm.; a depressed central space 
of 1.50 or 2 mm. in diameter, destitute of cell apertures and occupied by 
the minutely nodose mesopores. 
This species has a close resemblance to F. constricta, but may be distinguished 
from that species by the more distant cell apertures, much more prominent 
peristomes, more decidedly trilobate apertures, and the flat interapertural 
surface; it most nearly resembles F. unilinea, but it may be distinguished by 
the somewhat smaller, more elongate and decidedly trilobate cell apertures, 
