88 
PALAEONTOLOGY OF NEW YORK. 
.25 mm., width two-thirds the length; irregularly disposed, frequently in 
contact. Peristomes strong, equally elevated, sometimes with one or two 
comparatively strong nodes or spinules. Mesopores minute, usually only one 
series between adjacent apertures; margins the same height as those of the 
peristomes. Intercellular space vesiculose. 
This species may be distinguished from F. digita, of the Hamilton group, by 
its manner of growth, that species being always more or less digitate, the less 
closely disposed apertures and the absence of numerous spinules; from F. 
striata , it differs in its much smaller mesopores, those of that species some¬ 
times obscuring the apertures; from F. multiaculeata , it differs in having the 
apertures smaller, more broadly oval, and without the numerous spinules 
characteristic of that species. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
COSCINIUM, Keyserling. 1846. 
CoSCINIUM STRIATURUM. 
PLATE XXXIII, FIGS. 20, 21. 
Clathropora striatura , Hall. Report of State Geologist for 1SS2. Expl. pi. 26, figs. 20, 21. 1883. 
Zoarium consisting of lamellate expansions, celluliferous on each side; per¬ 
forated at regular intervals by oval fenestrules. Cell apertures oblique, sub- 
triangular, diameter .18 mm.; closely disposed, frequently alternating and 
imbricating: anterior portion of the peristome not elevated; posterior portion 
strongly elevated, projecting over and partially concealing the opening, and 
having two slight denticulations. Fenestrules oval, length about 2 mm., 
usually occurring at intervals of about 4 mm.; disposed in diagonally inter¬ 
secting rows. There is a space around each fenestrule destitute of aper¬ 
tures, much wider at the lower part of the fenestrule than above, and with 
low, broad ridges. The general direction of the cells is not interrupted by 
the fenestrules. 
This species is easily distinguished from Coscinotrypa carinata by the absence 
of lateral growths, and the general direction of the cells not being interrupted 
by the fenestrules. 
Formation and locality. Upper Helderberg group, Stafford, N. Y. 
