NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
207 
proximal border. The onyehocellarium is as large as the zooecia, falciform, acumi- 
nate, with an elliptical opesium. 
Measurements . — Opesium of [hon— 0.18 mm. ~ . ,, . 
, ■ 1 7 n -i Onyehocellarium 
no h nno n a / non — f I II m m ^ 
Onychocellaria \lon=0.10 mm. 
Opesia of [ ho =0.20-0.24 mm. 
zooecia 1 lo= 0.10-0. 14 mm. 
Zooecia 
\Lon=0A0 mm. 
)/<m=0.20 mm. 
[ Lz— 0.30-0.32 mm. 
1/2=0.20-0.24 mm. 
Affinities and variations . — This species is much smaller than OnychoceJia angu- 
iosa Reuss, 1867. Its polypidian convexity is scarcely apparent and disappears 
totally in the marginal zooecia where the opesium is then elliptical. 
Occurrence . — Lower Jacksonian: Three and one-half miles southeast of Shell 
Bluff post office, Georgia (rare). 
Cotypes.- — Cat. No. 63862, U.S.N.M. 
ONYCHOCELLA CELSA, new species. 
Plate 32, fig. 25. 
Description.— The, zoarium incrusts Cellepores. The zooecia are distinct, elon- 
gated, ogival, separated by a furrow or by a salient thread. The cryptocvst is 
deep, smooth, a little longer than the opesium ; the opesium is placed high, ogival ; 
the opesiular indentations are rather deep and nearly symmetrical. The onyeho- 
cellarium is as large as a zooecium, lozenge-shaped, somewhat falciform; the 
opesium is large, elongated, median, oval, the point below. 
Measurements . — Opesia fho=0 . 15 mm. 
of zooecia \7<?=0.12 mm. 
Opesia thon=0 . 25 mm. 
of onychocellaria \lon=0.1Q mm. 
Zooecia 
Onychocellaria 
1 7,2=0.40-0.45 mm. 
1 72=0.35-0.40 mm. 
j Zcui=0.45-0.50 mm 
| ion— 0.20-0.30 mm. 
Affinities .- — This species differs from Onychocella georgiana in its salient 
polypidian convexity. It differs from Onychocella angulosa Reuss, 1845, in its 
smaller micrometric dimensions, its less falciform onychocellaria, and its more 
symmetrical and regular opesium. From Onychocella laciniosa it may be dis- 
tinguished by its elongated and nontransverse opesium. 
The only specimen found has been figured. It is a very beautiful example 
of this genus. 
Occurrence . — Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 
Holotype. — Cat. No. 63958, U.S.N.M. 
ONYCHOCELLA LACINIOSA, new species. 
Plates 32, figs. 20, 27. 
Description . — The zoarium incrusts shells. The zooecia are hexagonal, con- 
fluent with one another by their mural rim. The cryptocyst is flat, smooth, 
depressed, longer than the opesium ; the opesium is semilunar, transverse ; the 
polypidian convexity is slightly projecting; the opesiular indentations are small 
and unsymmetrical. The onyehocellarium is falciform, narrow, as long as the 
