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. 



Occwmnce.— Lower Miocene (Bowden horizon) : Bowden, Jamaica (very com- 

 mon). Pleistocene or Recent: Vero, Florida (rare). 



Geologic distrilution.—Tovionmn of Austria Hungarj- (Manzoni). 



Habitat— Recent, off Florida (Smitt). 



Plesiotypes.— Cut. Nos. 68428, 68429, U.S.N.M. 



ACANTHODESIA SAVARTI forma DEUCATULA Busk. 1859. 



Plate 11, figs. 5-9. 



1859. Biflustra ddicatuh Busk, Monograph fossil Poly zoa of the Crag, Publications Paleontograph- 

 icalSociety, London,vol.l4,p. 72,pl.l,figs.2,4;pl.2,fig. 7. ^ . , , 



1869. Biflustra delicatula Manzoni, Bryozoi fossiU itaUani, Terza contribuzione, Sitzungsbenchte 

 der kaiserUchen Akademie der Wissenschaften, vol. 60, Abtheil. 1, p. 4, pi. 1, fig. 5. 



. (7^0 = 0.40 mm. Zooecia fi2 = 0.60nim. 



Measurements.— Oj>esi&i^ ^^ _ ^ 20 mm. (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 

 cryptocyst is abundant in the Mediterranian Phocene. 



Occi/mnce.— Miocene (Choctawhatchee marl':) Jackson Bluff, Ocklocknee 

 River, 25 miles southwest of Tallahassee, Florida (rare). Miocene (St. Marv^s for- 

 mation) : Bowler's wharf, 18 miles above Urbana, Middlesex County, Virginia (rare). 



Geologic distrilution.-Ilelvetmn of St. Avit and Salles (Gironde), of the faluns 

 of Touraine (Canu collection). Phocene (Astian) of England (Busk) and of Italy 

 (Manzoni) . 



Plesiotypes.—€iit. Nos. 68430, 68431, U.S.N.M. 



ACANTHODESU SAVARTI forma BITDLIATA llrich and Bassler. 1904. 



Plate 11, fig. 4. 



1904. Membranipora bifoliata Ulrich and Bassler, 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 bUamellar. Tubercles at the angles. 



This form is much like forma delicatnla 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 imilamellar forms. 



Occurrence.— Miocene (Choptank formation) : Jones wharf and Cordova. Mary- 

 land (common). 



Cotyfes.—C&t. No. 68432, U.S.N.M. 



