NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
155 
Geological distribution . — Priabonian of Vicentin (Waters) ; Helvetian of Tou- 
raine (collection Canu). 
Plesiotypes. — Cat. No. 63927, U.S.N.M. 
CALLOPORA VICINA, new species. 
Plate 81, figs. 2, 3. 
Description . — The zoarium incrusts bryozoa. The zooecia are elongated, dis- 
tinct, elliptical, or oval; the mural rim is quite salient, flat, very finely granular. 
The opesium is of the same form as the zooecium. The avicularia are distributed 
irregularly over the zoarium between the opesia ; they are oblique and their an- 
terior part is embedded in the mural rim, whereas their point projects considerably 
above the latter. 
Measurements . — Opesia 
| ho=0.30 mm. 
lfo=0.16 mm. 
Zooecia 
Ls=0A0 mm. 
0.26 mm. 
Variations . — The mural rim is rarely regular; more often it is a little enlarged 
at the base. The avicularia often exhibit two lateral denticles serving as a pivot 
for the mandible which can thus easily be placed between the mural rims, which 
are always separated by a deep furrow. On our specimens there are numerous 
zooecia with double mural rims, which have undergone total regeneration. 
Affinities . — This species is really close to Callopora tenuirostris Hindis. 1880, 
but differs from it in its much smaller avicularia. It appears to be intermediate 
between the Callopora lineata group and the G . tenuirostris group. 
Occurrence . — Vicltsburgian (“Chimney rock” of Marianna limestone'): One 
mile north of Monroeville, Alabama (common). 
Cotypes. — Cat. No. 64234, U.S.N.M. 
CALLOPORA (?) TUBEROSA, new species. 
Plate 3, fig. 14. 
Description . — The zoarium is free, unilamellar. The zooecia are little distinct, 
subcircular; the mural rim is salient, very thick, convex, and bears 6 to 8 large 
tuberosities entire or hollow. The opesium is oval, a little crenulated. The ovicell 
is hyperstomial. On the gymnocyst there are one or two large, projecting avicularia 
in which the orifice, turned toward the opesium, is perpendicular to the zooecial 
plane and consequently hardly visible. Between the zooecia there are long, thin 
avicularia without a pivot. 
Affinities . — This species is quite an unusual form and we have been unable to 
make a detailed study of it because the figured specimen is the only one known. 
Some of the interzooecial avicularia have a resemblance to Holoporella decostilsii 
Audouin, 1826, but are provided with a pivot. 
Occurrence . — Midwayan (Clayton limestone) : One mile west of Fort Gaines. 
Georgia (very rare). 
Holotype. — Cat. No. 63792, U.S.N.M. 
