NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
759 
Affinities. — This species differs from Tubulipora midicayanica in its less pro- 
jecting, irregular, and incomplete fascicles. In its general aspect it much resembles 
T ubvlipora lucida MacGillivray, 1881, from the Australian coasts. It differs from 
it in its less salient tubes and its more oblique peristomes. These are insignificant 
differences which a knowledge of the micrometric measurements of the Australian 
species might overcome. 
Occurrence. — Middle Jacksonian: Rich Hill, 5 1 miles southeast of Knoxville, 
Crawford County, Georgia (very rare). 
Holotype. — Cat. No. 65335, U.S.N.M. 
PLATONEA, new genus. 
Greek: platos , in allusion to the ovicell occupying the entire zooecial width. 
The ovicell is subsymmetrical, lobate, median, elongate, spread out between the 
fascicles over the entire zoarial width. The gemmation is linear. “ Oeciostome a 
short tube, developed on the 
proximal side of one of the 
series of zooecia, near its me- 
dian end. Oeciopore directed 
frontally, elongated trans- 
versely and more or less 
oval.” (Harmer, 1915.) 
Genotype. — Reptotubi- 
gera ' philrppsae Harmer, 
1915. 
Range. — Vicksburgian- 
Recent. 
Historical. — The form of 
the zoarium is that of an 
incrusting Idmonea. Noting 
the great difference between 
this ovicell and that of Tu- 
bulipora , Harmer in 1915, 
believed that the old genus Reptotubigera of D’Orbigny might be restored but 
unfortunately all the species of Reptotubigera have not the same ovicell and 
to our great regret we can recognize the genus of the French paleontologist only 
for those species deprived of ovicell, in conformity with his definition and figures. 
Affinities. — This genus differs from Idmonea , which has the same fascicular 
arrangement, in its lobate ovicell spreading between all the fascicles and not limited 
to a single median part of the zoarium. It differs from Tubulipora in its sub- 
symmetrical ovicell. in its tubes little projecting above the ovicell, and in its linear 
gemmation. 
Tubulipora serpens is provided with a zoarium like an incrusting Idmonea. 
It is not a Platonea because its ovicell is irregularly lobate, not subsymmetrical 
and because its small oeciostome is adjacent to any tube whatsoever. We repeatedly 
have to remark that the zoarial form is of no value for generic classification. 
B *20 
Fig. 248. — Platonea, new genus. 
A, B. Ovicelled lobe of Platonea (Reptotubigera) pliil- 
lipsae Harmer, 1915 o, oeciopore. 
