78 
BULLETIN OF THE LABORATORIES 
the most abundant of the bryozoa so far found in Waverly series, a de- 
scription is desirable in this place. I take the liberty, therefore, of 
appending my description of the species as it will appear in the work 
above cited. 
^‘Zoarium pinnate; midrib slender, usually straight, 0.4 to 0.45 
mm. wide, with the reverse side evenly rounded and finely striated. 
Obverse face low ridge-shaped, the mesial carina rounded, not promi- 
nent, with rather strong nodes at irregular intervals. Lateral branch- 
es from I to 2 mm. in length, like the midrib but only two-thirds as 
wide, opposite or sub-alternately given off from the sides of the mid- 
rib ; nine or ten in one cm. Zooecial apertures in two alternating 
ranges, fifteen in 5 mm., subcircular, with faintly elevated thin peris- 
tome, about o. I mm. in diameter. All the interspaces between the 
apertures very finely striated longitudinally.” 
Some of the Ohio specimens have the midrib as wide as o. 5 mm. 
The thinner midrib, larger lateral branches, and shorter zooecia 
distinguish this species from P. Youngi. 
Formation and locality: — The original types are from the Keo- 
kuk group at King’s Mountain, Ky. During the last year I have 
also found it in beds of the same age at Keokuk, Iowa. The Ohio 
specimens come from the Cuyahoga shales at Richfield, Lodi and 
Bagdad, Ohio. 
PINNATOPORA YOUNGI, 
(Plat^IV, Figs. 6, 6a.) 
Ptnnatopora yoitngi, Ulrich. Geol Surv. III. vol VIII, pi LXVI, fig. 3. (In press.) 
The following description is copied from my MS. for the work 
above cited. 
‘ ‘Zoarium pinnate, comparatively strong. Midrib strong, aver- 
aging o. 6 mm. wide, with the reverse side broadly convex and finely 
striated. Obverse side somewhat flattened, with a strong, rounded, 
mesial keel, bearing large but not prominent nodes at intervals of 
about 0.8 mm. Entire obverse face between the zooecia apertures 
very finely striated. Lateral branches short, at their origin about 
there-fourths as wide as the midrib, tapering rapidly toward their 
rounded distal extremity ; opposite or alternating, with eleven on each 
side in i cm., given off at an angle of from 60° to 80°. Zooecia in 
alternating ranges. Apertures subcircular, with a very thin and slight- 
