CORALS AND BRYOZOA. 
211 
fertipora by the more prominent and distant monticules, the larger and more 
distant sub-trilobate cell apertures, the stronger peristomes, the absence of 
nodes on the peristomes, and the comparatively indistinct mesopores: from 
F. serrulata by the larger cell apertures, their form and closer disposition, the 
much greater variation in the size of the apertures and the absence of serrula- 
tions on the peristomes. 
Formation and localities. Hamilton group, West Williams, Ontario, Canada; 
shore of Canandaigua lake, and York, Livingston county, N. Y. 
Fistulipora confertipora. 
PLATE LVIII, FIGS. 1-5. 
Thallostigma confertipora, Hall. Trans. Albany Institute, vol. x, p. 184. 18S1. 
“ “ “ Report of State Geologist for 18S3, p. 19. 1884. 
Zoarium consisting of explanate, free or incrusting fronds, or of masses formed 
by the superimposition of successive layers of growth; fronds varying from 
.50 to 5 mm. in thickness; the under surface consists of a thin, strongly 
wrinkled epitheca, from which the cells arise, obliquely for a short distance, 
but for nearly their entire length are rectangular to the surface ; cells tubular, 
cylindrical, septate, transverse section circular; septa thin, occurring at irreg¬ 
ular intervals, infrequent; cell walls thin, with numerous fine corrugations 
which frequently resemble nodes, about six in the space of 1 mm. Intercel¬ 
lular tissue composed of vesicles which are irregularly disposed near the base, 
becoming more regular above, having the appearance of narrow septate tubuli, 
from fifty to sixty septa in the space of 5mm. Cell apertures circular, diameter 
.30 mm., closely and irregularly disposed, very frequently in contact. Peri¬ 
stomes moderately strong, distinctly and equally elevated, when well 
preserved having several short spines, which sometimes form the most con¬ 
spicuous feature of the surface. Mesopores minute, usually only a single 
series between adjacent apertures; margins elevated slightly less than the 
peristomes. The surface is marked by low, rounded monticules, the centers 
of which are distant from each other about 4 mm., disposed in diagonally 
intersecting rows with their bases in contact. The cell apertures on the 
