714 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
It differs from Diastopora tubiforviis in which the zoarium is almost identical, 
in the absence of overlapping wrinkles on the tabes, and in the presence of a sep- 
arating thread between the tubes. 
Occurrence. — Middle Jacksonian (Castle Jlavne limestone) : Wilmington, 
North Carolina (rare). 
Cotypes. — Cat. No. 65275, U.S.N.M. 
PLAGIOECIA LAMELLOSA, new species. 
Plate 122, figs. 10-13. 
Description. — The zoarium is unilamellar. The tubes are indistinct at their 
base, cylindrical, rectilinear, striated, terminated by a very oblique peristomie, 
arranged in quincunx ; the peristome is orbicular and oblique or more often elliptical 
and horizontal. The ovicell is convex, transverse, in the form of a crescent whose 
convexity is proximal and not parallel to the zoarial margins. No zone of growth 
is visible. 
f Diameter of the peristome 0.12 mm. 
Measurements. — Distance between the peristomes 0.50 mm. 
I Separation of the peristomes 0.58 mm. 
Affinities. — The difference between this species and Diastopora striatisemota is 
very slight; they perhaps represent the same species. The present species differs 
from it in its larger zooecial diameter (0.12 and not 0.10 mm.) and chiefly in tlie 
great separation of the peristomes (0.58 and not 0.40 mm.). This has the same 
ovicell as Plagioecia botula , but it differs from it in its peristome of 0.12 and not 
0.16 mm. More numerous specimens will permit us perhaps to reunite these three 
species. 
Occurrence. — Middle Jacksonian (Castle Hayne limestone) : Wilmington, 
North Carolina (rare). 
Cotypes.— Cat. No. 65429, U.S.N.M. 
PLAGIOECIA BOTULA, new species. 
Plate 124, figs. 1, 2. 
Description. — The zoarium is discoidal, incrusting shells, and emits flabelliform 
expansions. The tubes are distinct, long, cylindrical, or somewhat in the shape of 
a horn, bent upward at their extremity, arranged in regular quincunx, slightly 
striated, terminated by a short very oblique peristomie ; the peristome is orbicular 
or elliptical when the peristomie is incomplete. The ovicell is rectilinear, convex in 
the form of a sausage. The zone of growth is invisible. 
M easurements.- 
Diameter of the peristomes (when not salient) _ 0.12-0.16 mm. 
Distance between the peristomes 0.40-0.60 mm. 
Separation of the peristomes 0.40-0.50 mm. 
