NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 57 



FLORIDINA REGULARIS, new species. 



Plate 14, fig. 7, S. 



Description. — The zoarium incrusts shells and consists of one or two super- 

 posed lamellae. The zooecia are distinct, separated by a furrow, little elongated, 

 hexagonal, regular; the cry])tocyst is smooth, somewhat concave, limited laterally 

 by two convergent grooves which end at the opesiules. The apertura is orbicular 

 and forms the distal part of the trifoliate opesium; the polypidian convexity is 

 limited laterally by two linear opesiules. The pvicell is little salient and endo- 

 zooecial. The onychocellarium is fusiform; its beak is very salient on the zooecial 

 plane; its opesium is anterior. 



Lz = 0.40 mm. 

 lz = 0.35 mm. 



,, ... X rv • ^0 = 0.15 mm. „ 



Measurements (maximum) . — Opesia , . , „ Zooecia 



^ ?o = 0.12mm. 



Affinities. — The marginal zooecia are elongated; the central zooecia are 

 transverse. 



This species differs from Floridina antique Smitt, 1872, in its onychocellarium 

 with salient beak of a different form. It differs from Floridina parvicella in its 

 larger micrometric measurements. 



Occurrence. — Miocene (Duplin marl): Wilmington, North Carolina (common). 

 Natural Well, 2 miles southwest of Magnolia, Duplin County, North Carolina (com- 

 mon). Miocene (Yorktown formation): Yorktown, Virginia (rare). 



Hohtype and paratype.— Cat. Nos. 68475, 68476, U.S.N.M. 



FLORIDINA PARVICELLA, new species. 



Plate 31, fig. 12. 



Description. — The zoarium incrusts oysters. The zooecia are small, hexagonal, 

 little elongated, distinct but with adjacent mural rims; the opesium is trifohate; 

 the anterior part of aperture is elongate or elliptical; the polypidian convexity is 

 wide and limits two linear and transverse opesiules. 



,, , r^ ■ lAo = 0.10mm. „ . (1.2 = 0.38 mm. 



Measurements. — Upesia , _ „_ Zooeciai , „ „^ 



^ lw = 0.07mm. 1 fe = 0.30 mm. 



Affinities. — This species is sufficiently characterized by its small dimensions. 

 It differs again from Floridina regularis in the absence of a furrow separating the 

 zooecia. 



The genus Floridina has been observed in the Cretaceous formations of north- 

 em Europe. It has, therefore, in the course of the geologic ages migrated slowly 

 toward the Equator. The Waccamaw marl is its last known stage in America. 



Occurrence. — Pliocene (Waccamaw marl) : Waccamaw River, Horry County, 

 South Carolina (very rare). 



Holotype.— Cat. No. 68477, U.S.N.M. 



FLORIDINA MINIMA, new species. 



Plate 14, fig. 6. 



Description. — The zoarium incrusts shells. The zooecia are distinct, separated 

 by a furrow, very s7naU, hexagonal or ogival; the mural rim is wide, convex, little 

 salient, very finely granulated; the cryptocyst is of little depth, somewhat convex 

 12184— 23— Bull. 125 5 



