424 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



median avicularium. Canu 1 has already cited an analogous case of equilibrium in 

 Exochclla mutablis Canu, 1911, from the Kocanean 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 properly. The absence of prominent 

 threads separating the zooecia will suffice to differentiate it from all the others. 



A Bx20 



FIG. 125. Genus Oi/r/iVo/jon/ Ilincks, 1884. 



A-E. Cyclieoiiora longipora MaoGillivray, 1882. A. Ovlcelled 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. 



Oceuivence. Middle Jacksonian: Wilmington, North Carolina (common); 

 near Lenuds Ferry, South Carolina (very rare). 

 Ootypes.C&t. No. 64097, U.S.N.M. 



Genus CYCLICOPORA Hincks, 1884. 



1SS4. ('in-Hrn/iora HINCKS, Polyzna from Victoria, Annals and Magazine Natural History, 

 ser. 5, vol. 14, p. 279; 1893. ser. G. 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 



1 Iconographie Bryozoaires fossiles de 1'Argenttne, pt. 2. Anales del Museo National de Buenos 

 Airi's, vol. 21, p. 263. 



