OF DENISON UNIVERSITY. 
77 
The sub-angular character of the reverse distinguishes this species 
from all others known to me. In other respects it resembles P. tenui- 
ramosa very closely. P. Vinei also is a nearly related species but, 
aside from the different form and markings of the reverse, is disting- 
uished by the smaller number of pinuce and zooecia in a given space. 
Formation and locality : — Cuyahoga shales of the Waverly series, 
about 30 feet below the Carboniferous conglomerate at Cuyahoga 
Falls. 
PINNATOPORA MINOR, n.sp. 
(Plate XIV, Fig. 7, 7a.) 
Zoarium very small, pinnate. Midrib about 0.32 mm. wide, 
throwing off the pinnse sub-alternately from the two sides, at an angle 
of nearly 80° .The latter are short, less than i mm. long, about 0.19 
mm. wide, and eight or nine on each side in 5 mm. Reverse side of 
midrib broadly rounded or somewhat flattened along the middle, and 
marked by three fine longitudinal striae, bordered on each side by a 
smooth space. Obverse face ridge-shaped, the carina comparatively 
strong and bearing inconspicuous nodes at intervals a little longer 
than a zooecium. Zooecia in two ranges, with subcircular or elliptical 
apertures, about 0.09 mm. in diameter, with moderately developed 
peristome, much the highest on the outer side. The apertures are ar- 
ranged one at the base of each lateral branch and one in the interme- 
diate space, with about sixteen on each side of the midrib in 5 mm. 
This neat species resembles P. Younoi^ Ulrich,* in nearly every 
respect excepting size, that being one of the most robust forms of the 
genus while this is one of the smallest. Its diminative fronds are 
easily distinguished from the associated species. 
Formation and locality : — Upper beds of the Cuyahoga shales, 
at Richfield, O. 
PINNATOPORA VINEI. Ulrich. 
(Plate XVI, Fig. 5.) 
Pinnatopora Ulrich. Ill, Geol. Surv. vol. VIlI, pi. LXVI, figs. 5, 5b. (In 
l^ress } 
I cannot see that the Ohio specimens of this species differ in any 
essential respect from the Kentucky and Illinois types. Being one of 
