424 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
1 Ieonographie Bryozoaires fossiles de 1’ Argentine, pt. 2, Anales del Museo Nacional de Buenos 
Aires, vol. 21, p. 283. 
median avicularium. Canu 1 has already cited an analogous case of equilibrium in 
Exochella mutablis Canu, 1911, from the Rocanean of Argentina. The olocyst is . 
very thick (pi. 55, fig., 5). Finally we have observed two monstrous zooecia 
(pi. 55, fig. 3). 
Affinities . — This species is very deceiving, and, without the study of the zooecial 
interior, it would be impossible to classify it property. The absence of prominent 
threads separating the zooecia will suffice to differentiate it from all the others. 
Fig. 125. — Genus Cyclicopora Hindis, 1SS4. 
A-E. Cyclicopora longipora MacGillivray, 18S2. A. Ovicelled zooecia. (After MacGilli- 
vray, 1882.) B. Zooecia, X 20, indicating that the lateral pores are areolar. C. Tangential 
section of the inner face of the frontal wall, X 48, showing the tremopores along the suture 
lines. D. Tangential section of the external face of the frontal wall, X 48. (After Hennig, 
1910.) E. Operculum showing the border very thick and chitinous. 
Occurrence . — Middle Jacksonian: Wilmington, North Carolina (common); 
near Lenuds Ferry, South Carolina (very rare). 
Cotypes.— Cat. No. 64097, TJ.S.N.M. 
Genus CYCLICOPORA Hincks, 1884. 
1884. Cyclicopora Hinciis, Polyzoa from Victoria, Annals and Magazine Natural History, 
ser. 5, vol. 14, p. 279 ; 1S93, ser. 6, vol. 12, p. 143. 
The ovicell is hyperstomial and always closed by the operculum. The frontal 
is a tremocyst with pores in quincunx. There are no cardelles, but the operculum 
