28 
PALEONTOLOGY OF NEW YORK. 
consisting of a strongly wrinkled epitheca. Cells tubular, arising from and 
for a short distance oblique to the epitheca, then turning abruptly upward ; 
walls very thin. Septa infrequent or entirely wanting. Apertures circular, 
diameter slightly more than .25 mm. ; irregularly, very closely disposed, fre¬ 
quently in contact: margins thin, slightly elevated, ornamented with from 
one to three very prominent spines. Mesopores very minute: margins thinner 
than those of the apertures, but of the same height. Intercellular space 
vesiculose; vesicles irregularly arranged, comparatively very large, frequently 
from .25 to .33 mm. in diameter. 
This species may be distinguished by its closely arranged circular cell aper¬ 
tures with spiniferous margins, in which characters it varies from any other 
species of this formation. 
Formation and locality. In the shaly limestone of the Lower Helderberg 
group, near Schoharie, N. Y. 
Fistulipora parasitica. 
PLATE XIV, PIGS. 13,14 ; AND PLATE XXIII, PIG. 4. 
In part Callopora ‘parasitica, Hall. Thirty-second Rept. N. Y. State Mas. Nat. Hist., p. 157. 1879. 
“ “ “ “ Report of State Geologist for 1S82. Expl. pi. 14, tigs. 13-18. 1883. 
Zoarium explanate, or ramose, with hollow branches, free or encrusting other 
bodies. Thickness .75 mm.; inner, or under surface consisting of a thin, con¬ 
centrically wrinkled epitheca. Cells tubular; apertures oval or slightly 
polygonal from mutual pressure, length from .25 to .33 mm., width from .17 
to .25 mm.; very irregularly disposed, sometimes in contact, at other times 
distant .50 mm. or more: margins thin, slightly and equally elevated; fre¬ 
quently with one or more minute spinules. Mesopores variable in size, some 
having a diameter of only .10 mm., while others are equal to the cell aper¬ 
tures : margins of the same thickness and height as those of the cell aper¬ 
tures. Intercellular space vesiculose; vesicles sometimes regularly arranged, 
appearing as septate tubuli; at other times irregular, especially near the base 
of the cell tubes. 
