560 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
In the interior the aperture is semilunar and transverse with a slightly concave 
proximal border. 
In examining the figures of Reuss we can note only a few differences of little im- 
portance; the interareolar costules appear less salient and the avicularium there 
appears smaller and more removed from the external aperture. At the most, our 
specimens form a variety. 
Occurrence. — Middle Jacksonian: Eighteen miles west of Wrightsville, Johnson 
County, Georgia (rare) ; Rich Hill. 5J miles southeast of Knoxville, Georgia (rare) ; 
12 miles southeast of Marshallville, Georgia (rare) ; one-half mile southeast of 
Georgia Kaolin Company Mine, Twiggs County, Georgia (rare). 
Geological distribution. — In Europe the species occurs in the Latdorfian of 
Latdorf (Reuss), Rupelian of Germany (Reuss), Chattian of Germany (Reuss). 
Fig. 167. — Genus Adeona Lamouroux, 1816. 
A-F. Adeona violacca Johnston, 1S49. A. Portion of zoarium, X 22, showing numerous 
marginal zooecia with frontal wall still uncalcified. B. Four zooecia, X 40, two of which have 
the avicularium replaced by an elongated cavity which opens by means of a round pore. C. Three 
zooecia, X 40, viewed from the basal side after removal of the basal surface. The primary 
aperture and the proximal margin of the secondary are visible. D. Avicularian mandible, X 
100. E. Two gonoecia, X 40, furnished with a cavity instead of an avicularium, like the zooecia 
in fig. B. F. Operculum, X 75. The transverse oval part, somewhat more chitinized. corresponds 
with the secondary aperture. (A-F after Levinsen, 1909.) 
These three are the substages of the Tongrian. Finally, Reuss cited it from the Tor- 
tonian of Wieliezka in Pologne, but he did not give a figure. 
Cotypes.- — Cat. No. 64190, U.S.N.M. 
Genus ADEONA (Lamouroux, 1816) Levinsen, 1909. 
1909. Adeona Levinsen, Morphological and Systematic Studies on Cheilostomatous Bryozoa, 
p. 283. 
The frontal is perforated by an ascopore opening into the compensatrix. The 
operculum is semilunar. The gonoecia are distinct and larger than the ordinary 
zooecia. 
Genotype. — Adeona ( Celle pora ) heckeli Reuss, 1847. 
