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PALAEONTOLOGY OF NEW YORK. 
strongly and regularly corrugated ; corrugations sharp, five in the space of 
1 mm. Septa extremely thin, in some cells moderately frequent, in others 
obsolete. Intercellular tissue vesiculose ; the vesicles near the base are large 
and very irregularly disposed, they are smaller above and more regularly 
superimposed, frequently having the appearance of septate tubuli, with strongly 
corrugated walls. A transverse section shows the cells to be cylindrical, 
frequently partially in contact and the ordinary cells never distant more than 
.10 mm. Cell apertures circular, diameter .30 mm., very closely and usually 
irregularly disposed, but sometimes forming sub-regular curved lines on the 
monticules, generally distant a little more than one-fourth the diameter of 
an aperture. Peristomes usually obsolete. Inter-apertural space elevated ? 
angular, sometimes with minute nodes at the angles, giving to the apertures 
a polygonal appearance, much resembling those of some form of Favosites. 
Surface marked by broad, convex monticules, the centers of which are distant 
from 5 to 8 mm., and have a granulose circular area, about 1.75 mm. in 
diameter, destitute of cell apertures. The apertures immediately adjacent 
are a little larger and more distant than the others, a little oblique and with 
very thin peristomes, the posterior portions of which are the stronger, with 
evidences of very slight denticulations; the space between these apertures 
is somewhat flattened and sometimes with a very slender striation. 
This species may be distinguished from Fistulipora constrida by the broader, 
more distant monticules, the larger cell apertures, destitute of peristomes 
and denticulations, the smooth interapertural space and the absence of 
mesopores: from F. unilinea it is distinguished by the more prominent monticules, 
the absence of peristomes and denticulations and the angulated inter-apertural 
space without mesopores; nearly the same features will distinguish it from F. 
interaspera. From any other species at present known, in the Lower and 
Upper Helderberg and Hamilton groups, it may be distinguished by the circular, 
closely disposed cell apertures without peristomes or denticulations, and the 
smooth angular, inter-apertural space, giving to the apertures an appearance 
similar to those of some forms of Favosites. 
Formation and locality. Hamilton group, Genesee Valley, N. Y. 
