Bulletin - United States National Museum - Smithsonian Institution

20 BULLETIN 96, UNITED STATES NATIONAL MUSEUM.
Afjinitks.—The dietellae open into the zooecia in large pores which
are really the remains of multiporous septulae. The ovicell is rare
and very small.
The species differs from Ellisina (Semifiustrella) rhomhoidalls
D'Orbigny in its dimensions twice as large and in the ogival and
nonrhomboidal form of the zooecia. It is the largest known species of
Ellisina.
Occurrence.—Middle Jacksonian: Wilmington, North Carolina
(very rare).
Upper Jacksonian (Ocala limestone) : 1^ miles above Bainbridge,
Georgia (rare).
Vicksburgian : Salt Mountain, 5 miles south of Jackson, Alabama
(very rare).
Tt/pe.—Cat. No. 62580, U.S.N.M.
GRAMMELLA Canu, 1916.
1916. Grammella Canu, Bulletiu Societe G^ologique de France (4),
vol. 16.
The operculum closes the ovicell. The avicularium is interzoopcial,
large, with a solid pivot ; its form recalls that of the Greek letter 0.
No dietellae.
Genotiipe.—Memhranipora crassimarglnata Hincks, 1880.
Range.—Santonian-Recent.
GRAMMELLA TRANSVERSA, new species.
Plate 2, fig. 6.
Description.— ^The zoarium incrusts bryozoa. The zocecia arc but
little elongated, broad, distinct; the mural rim is thin, sharp edged,
regular. The opesium is of the same form as the zocecium. The
ovicell is salient, globular, smooth, and carinated. The avicularium
is interzooecial, small, elliptical, and the pivot is neA'er median; its
longitudinal axis is transverse with respect to the zooecial axis.
J,, ^ /-. • [Ao=0.45 mm.
Measurements.—Opesia{, i
^.o^ /^^/^
[ Z6»= 0.35-0.40 mm.
. r, fZ:s=0.55-0.60 mm.
Zocecia , „ .„ „,„
I 7s =0.46-050 mm.
Affinities.—The aviculariiun is generally elliptical but it is some-
times triangular. The mural rim exhibits a rare and interesting
peculiarity. It is not provided with a side which merges into the
zocecium so that the opesium is bounded by the termen itself of the
mural rim. The present form differs from other described species of
Grammella in its small avicularia transversely oriented.
Occurrence.—Middle Jacksonian: Wilmington, North Carolina
(\^ery rare).
Tijpe.—Q^t. No. 62579, U.S.N.M.