NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
683 
measure 0.10 mm. in diameter. The mesopores are numerous and polygonal. In 
sections the tubes are cylindrical, the walls are not vesicular. The mesopores 
are short, regular and parietal. 
( Diameter of the orifices 0.10 mm. 
Distance between the orifices 0.50 mm. 
Diameter of the branches 2.00 mm. 
Affinities . — This is a very disconcerting species. The tubes are cylindrical 
and yet the walls are not vesicular; they are simply separated by a sort of small 
canal resulting from the disappearance of the ectocyst; this is the habitual ar- 
rangement of the club-shaped tubes. The zoarial walls are regular as in the zoarial 
form Petalopora , and sometimes lamellar (in transverse section) as in Hornera. 
The mesopores are regular, parietal as in the forms P etalopora and Sparsicavea , 
which also have the club-shaped tubes. 
This mingling of peculiar characters of the different families appears to indi- 
cate that this species must be ovicelled. Unfortunately we have not found many 
specimens of it. 
This species differs from Parascosoecia consimilis Ulrich, 1882, in a greater 
diameter of the orifice (0.10 and not 0.08 mm.) in its solid and never hollow 
branches, in its much less numerous and shorter mesopores, and in its cylindrical 
tubes. 
It differs from Parleiosoecia jacksonica , in which the exterior aspect is identical, 
in its solid branches, its much shorter mesopores, and its cylindrical tubes. 
Although very close to Ii eteroporct subreticulata Reuss, 1869, it differs from it 
in the exterior aspect of the mesopores, which, however, do not conform to the 
published figures. 
Occurrence . — Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 
Middle Jacksonian: Three and one-half miles north of Grovania, Georgia 
(rare) ; one-half mile southeast of Georgia Koalin Company’s Mine, Twiggs County, 
Georgia (rare). 
Cotypes. — Cat. No. 65371, U.S.N.M. 
HETEROPORA AMOENA De Gregorio, 1890. 
Plate 113, figs. 16-18. 
1890. Entalopliora amoena De Gregorio, Monographie de la Faune Eocenique de 1’ Alabama 
et surtout de celle de Claiborne de l’etage Parisien, Annales de Geologie et de 
Paleontologie, livr. 8, p. 240, p. 39, fig. 21. 
Description . — The zoarium is free, subcylinclrical, hollow, ornamented with 
large lateral and alternate apophyses, forming pseudobranches. The orifices are 
orbicular, widely spaced, and measure 0.10 mm. in diameter. The mesopores are 
numerous, irregular, polygonal. The tubes are cylindrical. 
Affinities . — We believe that this species is Entaloplxora amoena de Gregorio, 
1890, for it has the same lateral apophyses and the same cellular surface. To be 
