NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
819 
1852. Unicavea grignonensis D’Orbigny, Paleontologie frangaise, Terrains eretace, Bryozo- 
aires, p. 971. 
1S52. Discocavea pamensis D'Orbingy, Paleontologie frangaise, Bryozoaires, p. 958. 
1852. Radiotubigera grignonensis D’Orbigny, Paleontologie frangaise, p. 756. 
1852. Discocavea crispa D’Orbigny, Paleontologie frangaise, p. 95S. 
1886. Discoporella grignonensis Pergens and Meunier, Les Bryozoaires du Systeme 
Montien, Louvain, p. 14. 
1909. Lichenopora grignonensis Canu, Bryozoaires tertiares des environs de Paris, Annales 
de Paleontologie, vol. 5, p. 134, pi. 17, figs. 3-7. 
Description. — The zoarium is simple, free, and discoidal or composite incrust- 
ing, formed of a lamella with adjacent subcolonies. The basal lamella is thick and 
striated concentrically. The central area is large and concave. The fascicles are 
salient, solely in the vicinity of the central area; they are uniserial, short, and never 
reach the zoarial margins. The tubes are small, recumbent, provided with a visor; 
they are arranged in quincunx in the vicinity of the zoarial margins. The cancelli 
are polygonal and small. The ovicell placed in the central area covers over the 
cancelli. 
Measurements . — 
Diameter of the cancelli 0.06-0.10 nun. 
Diameter of the tubes 0.10 mm. 
Maximum diameter of the simple zoaria 0.75 mm. 
Affinities. — This species is evidently the Lichenopora hispida Fleming, 1828, 
universally distributed throughout all the seas of the globe. The variations noted 
in this species are so extraordinary that a revision of the known specimens appears 
necessary. The oeciostome figured by Hincks has not been rediscovered ; the ovi- 
celled specimens from the Mediterranean have never shown it. The arrangement 
in quincunx of the tubes on the zoarial margins does not therefore appear as a 
sufficient specific character if it is not supplemented by the character of the ovicell, 
the oeciostome, and the cancelli. In adopting the name Lichenopora grignonensis 
we are certain of having made a good identification, the comparison of the speci- 
mens having been made directly. Some subsequent studies will make the synonyms 
more specific. 
The composite zoaria appear to incrust algae, forming a greater or less thick- 
ness with many lamellae superposed. Two specimens from Cocoa post office, 
Choctaw County, Alabama, are hollow and measure 6 by 2-1 centimeters. 
Occurrence. — Midwayan (Clayton limestone) ; Luverne, Crenshaw County, 
Alabama (common) ; 1 mile west of Fort Gaines, Georgia (rare). 
Claibornian: Claiborne, Alabama (very rare). 
Jacksonian: Three and one-half miles southeast of Shell Bluff post office, 
Georgia (common). 
Lower Jacksonian (Moodys marl): Jackson, Mississippi (common). 
Middle Jacksonian: Wilmington, North Carolina (very common); near 
Lenuds Ferry, South Carolina (very common) ; Eutaw Springs, South Carolina 
(common) ; 18 miles west of Wrightsville, Johnson County, Georgia, (rare) ; Rich 
Hill, 51 miles southeast of Knoxville, Crawford County, Georgia; 31 miles south of 
Perry, Georgia (rare). 
