Bulletin - United States National Museum - Smithsonian Institution

EARLY TERTIARY CHEILOSTOME BRYOZOA. 49
by the oral aviciilarium. The apertiira is elongated, ovoid, very-
oblique. The oral aviculariiim is large, transverse, salient, with the
beak strong and curved; it is provided with a pivot and a large
mandible, more or less spatulate. On the frontal there are two
small, elliptical avicularia with round mandible.
Occurrence.—Vicksburgian : One mile north or Monroeville, Alabama
(very common).
Type.—C2.t. No. 62597, U.S.N.M.
METROCRYPTA, new genus.
{Metra^ womb, in reference to the ovicell; cryptos^ hidden.)
The frontal is a tremocyst with tubules. The rimule-spiramen is
wide and of very little depth. Ovicell unknown.
Genotype.— Metrocrypta hucculenta^ new species. Jacksonian.
The ovicell of this genus is unknown ; it is therefore very doubtful
that the genus should be introduced into this family. The oral avicularium
is very rare; however, its presence seems to us the best
character for classification.
METROCRYPTA BUCCULENTA, new species.
Plate 5, fig. 2.
Description.—The zoarium is free, cylindrical, bifurcated. The
zooecia are elongated, large, little distinct; the frontal is convex,
porous, formed of a tremocyst placed on a thick olocyst. The peristomice
is somewhat elongated, oval, its lower point formed of a wide
rimule-spiramen; the peristomie is somewhat salient; the apertura
(interior) is much smaller, orbicular, very oblique. The oral avic-
ularium is very rare; it is quite large, prominent, triangular, adja-
cent to the peristomice, provided with a pivot placed very low.
. •
-r. . / • ^ N fAi»e= 0.30-0.35 mm.
Measurements.—Feristomice (exterior) / „ „ „
'^
^ \lpe=Q.2>0 mm.
fAffl=0.15 mm.
. ^ /• . •
X
Apertura (mterior) , „ . „
^ ^ ' [m=0.15 mm.
„ .
(Z2=1.00
mm.
Zooscia , - „j.
|fe=1.25 mm.
Occurrence.—Middle Jacksonian (Castle Hayne limestone) : Wilmington,
North Carolina (common).
Type.—Oiii. No. 62598, U.S.N.M.
OCHETOSELLA, new genus.
{Ochetos^ small canal.)
The ovicell is hyperstomial and deeply embedded in the distal
zooecium. The rimule-spiramen is replaced by a small canal sup-
52091°—17 4