Bulletin - United States National Museum - Smithsonian Institution

EARLY TERTIARY CHEILOSTOME BRYOZOA. 67
In 1900 Waters ^ discovered the larva of Phylactella. It is quite
distinct from all others in its form and its large dimensions, evidently
characterizing a special family.
The special ovicell which Waters called recumbent is placed on the
distal part of the zooecium itself, between the apertura and the distal
zocecium. Viewed laterally it appears attached like a sack on the
back of a porter. Evidently it is also more or less supported on the
distal zocecium, but frequenty it is completely separated from it.
In its form, position, and large opening it is eminently adapted to
the size of the larvae.
Genus PHYLACTELLA Hincks, 1880.
1880. Phylactella Hincks, British Marine Polyzoa, p. 356.
The apertura is more or less circular; it bears either a lyrule or
some cardelles. The thick band of the operculum is at a small dis-
tance from the edge. The apertura is surrounded by a peristomie
more or less funnel shaped. The peristome is interrupted distally and
replaced by a small tongue. The frontal is a tremocyst with very
fine pores. No spines.
Genotype.—Phylactella lalrosa Busk, 1852.
Range.—Jacksonian-Recent.
In addition to the one here described three new species have been
determined in the Early Tertiary rocks of the Carolinas and Alabama.
PHYLACTELLA INFUNDIBULUM, new species.
Plate 6, fig. 2.
Description.—The zoarium incrusts other bryozoa. The zooecia
are large, distinct, elongated, oval ; the frontal is quite convex ; it is
formed of a tremocyst with very small pores separated from each
other by fine granules. The apertura is formed of a large semicir-
cular anter, separated by two small cardelles from a very concave pos-
ter ; the peristome is long, tubular, depressed in front, and interrupted
behind by a wide distal tongue ; the peristomie forms a sort of funnel
around the apertura.. The ovicell is large, salient, globular, finely
porous and granular; it is hyperstomial, recumbent, and opens into
the peristomie.
MeasureTnents.—Apertura ^
, r> i r> a i t
[ Za=0.16-0.17 mm.
Z2=1.25 mm.
Zoceciai , „ „„
^^=0.