NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 
33 
Affinities.—The presence of the spinous processes differentiates our specimens 
from FlustreUaria texturata from the European Tortonian which, according to the 
figures, does not bear them. 
Occurrence. —Lower Miocene (Bowden horizon): Bowden, Jamaica (very com¬ 
mon). Pleistocene or Recent: Vero, Florida (rare). 
Geologic distribution.— Tortonian of Austria Hungary (Manzoni). 
Habitat. —Recent, off Florida (Smitt). 
Plesiotypes. —Cat. Nos. 68428, 68429, U.S.N.M. 
ACANTHODESIA SAVARTI forma DELICATULA Busk. 1859. 
Plate 11, figs. 5-9. 
1859. Bijlustra delicatula Busk, Monograph fossil Polyzoa of the Crag, Publications Paleontograph- 
ical Society, London, vol. 14, p. 72, pi. 1, figs. 2, 4; pi. 2, fig. 7. 
1869. Biflustra delicatula Manzoni, Bryozoi fossili italiani, Terza contribuzione, Sitzungsberichte 
der kaiserlichen Akademie der Wissenschaften, vol. 60, Abtheil. 1, p. 4, pi. 1, fig. 5. 
Measurements .—Opesia 
(7to = 0.40 mm. 
I lo = 0.20 mm. 
Zooecia jZ 2 = 0.60mm. 
(first of series) | Iz = 0.40 mm. 
Our specimens have very narrow fronds. The mural rim is thick and finely 
tuberous. The cryptocyst is sometimes short, sometimes long. The traces of 
spinous processes are quite frequent. 
The bilamellar form commences in the Helvetian. The variation with large 
crvptocyst is abundant in the Mediterranian Pliocene. 
Occurrence. —Miocene (Choctawhatchee marl*':) Jackson Bluff, Ocklocknee 
River, 25 miles southwest of Tallahassee, Florida (rare). Miocene (St. Marys for¬ 
mation) : Bowler’s wharf, 18 miles above Urbana, Middlesex County, Virginia (rare). 
Geologic distribution. —Helvetian of St. Avit and Salles (Gironde), of the faluns 
of Touraine (Canu collection). Pliocene (Astian) of England (Busk) and of Italy 
(Manzoni). 
Plesiotypes. —Cat. Nos. 68430, 68431, U.S.N.M. 
ACANTHODESIA SAVARTI forma BIFOLIATA Ulrich and Bassler, 1904. 
Plate 11, fig. 4. 
1904. Membranipora bi/oliata Ulrich and Bas»er, Bryozoa, Maryland Geological Survey, Miocene, 
p. 411, pi. 112, figs. 2, 3, 4. 
There are areal spines. The opesium is surrounded by a sort of salient collar. 
The mural rim is thin. The zoarium is bilamellar. Tubercles at the angles. 
This form is much like forma delicatula and differs only in the absence of the 
cryptocyst and in its thin mural rim. The collar-like structure which surrounds the 
opesium is not constant; it exists sometimes in the unilamellar forms. 
Occurrence. —Miocene (Choptank formation): Jones wharf and Cordova, Mary¬ 
land (common). 
Cotypes. —Cat. No. 68432, U.S.N.M. 
