NORTH AMERICAN EARLY TERTIARY BRYOZOA. 765 
Affinities. — Tlxis species differs from Erkosonea semota in the lesser distance of 
the fascicles from each other and in the presence of the radicular lamellae. 
Occurrence. — Middle Jacksonian: Wilmington, North Carolina (very com- 
mon) ; near Lenuds Ferry, South Carolina (rare) ; Eutaw Springs, South Carolina 
(rare). 
Upper Jacksonian (Ocala limestone) : West bank Sepulga Biver, Escambia 
County, Alabama (rare). 
Cotypes. — Cat. No. 65357, U.S.N.M. 
PLEURONEA, new genus. 
Greek : pleuron , side, referring to the position of the ovicell. 
The ovicell is situated laterally on one-half of the basal lamella and between 
the fascicles on a single side of 
the median axis. The oeciopore 
appears to be the first tube of a 
fascicle. The basal surface is 
provided with large tergopores 
generally imperfectly oriented. 
The zooecia are grouped in fas- 
cicles, arranged symmetrically 
on each side of the zoarial axis. 
Genotype. — Ichnonea, fenes- 
trata Busk, 1859. 
Rang e . — M idw ay an- Asti an . 
This genus differs from 
Mesonea not only in the lateral 
position of the ovicell but also in 
the nature of the canals which 
reinforce the basal lamella. If 
one can generalize Busk’s figure, 
1859, these canals would be closed at their extremity by a calcareous, porous 
lamella extremely fine and fragile. 
PLEURONEA FIBROSA, new species. 
Fig. 251. — Pleuronea, new genus. 
Views of Pleuronea ( Idmonea ) fenestrata Busk, 
1859, from the Crag of England, showing the zoarium 
natural size, the frontal side enlarged, cross section of a 
branch and the frontal and dorsal sides much enlarged. 
(After Busk, 1859.) 
Plate 107, figs. 2-9. 
Description . — The zoarium is free, idmoneiform, bifurcated, with oval cross 
section. The fascicles are salient, uniserial, crowded and formed of five tubes at 
the maximum. The tubes have a visible peristomie; the peristome is round or 
rectangular. The basal lamella bears a thick layer of tergopores, the orifices of 
which are irregular but arranged longitudinally, and give a fibrous aspect to the 
zoarium. The ovicell is globular, salient, porous. 
„ , , Peristome 
Measurements . — j . , , .. „ . , 
I Distance between the fascicles 
0.10 mm. 
0.20 mm. 
