744 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
peristome is elliptical, thin, horizontal. The ovicell is globular, placed around 
some tubes, ornamented with wrinkles like the tubes. 
(Diameter of the peristome 0.10 mm. 
Measurements . — Distance between the peristomes 0.60 mm. 
I Separation of the peristomes 0.40-0.50 mm. 
This superb species is well characterized. 
Occurrence . — Vieksburgian (Marianna limestone) : Three miles southeast of 
Vosburg, Jasper County, Mississippi (rare). 
Ilolotype. — Cat. No. 65381, U.S.N.M. 
DIAPEROECIA ORBICULATA, new species. 
Plate 153, figs. 9-15. 
Measurements- 
D ascription . — The zoarium is free, large, orbicular; the basal lamella is 
striated concentrically. The tubes are distinct, cylindrical, rectilinear, arranged 
in quincunx or more often in irregular radial rows; the peristome is thin, orbicular, 
very oblique. The ovicell is large, transversely elliptical, more or less distant 
from the zoarial margins. 
Diameter of the peristome 0.10 mm. 
Separation of the jieristomes 0.36 mm. 
Distance between the peristomes in quincunx. 0.40-0.50 mm. 
Distance between the peristomes in rows 0.25-0.30 mm. 
This beautiful species is admirably characterized by its zoarium in the 
Discoparsa form and by its zooecia arranged in radial rows. We have discovered 
one specimen with an absolutelj' smooth ovicell. 
O ccurrence . — Vieksburgian (Marianna limestone) : One mile north of Monroe- 
ville, Alabama (very common). 
Cotypes. — Cat. No. 65382, U.S.N.M. 
DIAPEROECIA CLAVA, new species. 
Plate 154, figs. 1-9. 
Description . — The zoarium is a multiserial, thick Prohoscina form in which 
the branches are short or elongated and are in the form of a club ; it incrusts shells, 
bryozoa, Orbitoid foraminifera, and algae. When the zoarium is free, the basal 
lamella is striated transversally. The tubes are indistinct, arranged in regular 
quincunx, terminated by a very salient peristomie and elevated almost vertically. 
The peristome is orbicular, thick, sharp. The ovicell is very large, very globular, 
irregularly elliptical; the oeciostome is elliptical, transverse, directed proximally, 
adjacent to a tube. The zone of growth is very thick. 
Diameter of the peristome- . 0.10-0.12 mm. 
Diameter of the apertura 0.06-0.08 mm. 
Measurements . — ■ Distance between the peristomes 0.30 mm. 
Separation of the peristomes 0.30-0.36 mm. 
Width of the branches 1.5 mm. 
