622 BULLETIN 106, UNITED STATES NATIONAL ilUSEUM. 



only on the bilamellar zoaria (pi. 1<>1, fijr. 3). they are visible in transverse sec- 

 tions (pi. 102, fig. 2) or longitudinal sections (pi. 102, fig. 4) of the other zoaria. 

 There are all sorts of transitions between the frontal avicularia (pi. 101, fig. 4) and 

 the interzooecial avicularia. The zoarium may attain H centimeters in length and 

 may be considered as a good-sized fossil, easy of determination in the field. 



In tangential sections (pi. 102, fig. 3) the zooecial walls are seen to be formed 

 of very dense olocystal elements. 



Affinities. This species differs from Kleidionella cristata, in which the fronds 

 have almost the same form, in its larger cumulate zooecia, never grouped especially 

 in the middle of the fronds, and in the rarity of the oriented zooecia uniquely ar- 

 ranged at the extremity of the branches. 



It differs from Kleidionella lobata in the presence of its numerous cumulate 

 zooecia. 



Occurrence. Vicksburgian (" Chimney rock '' member of Marianna lime- 

 stone) : One mile north of Monroeville. Alabama (extremely common). 



Cotypes. Cat. No. 64327, TJ.S.N.M. 



Family CONESCHARELLINIDAE Levinsen, 1909. 



The. zooecia are erect; the apertura is terminal. The gemmation is always and 

 uniquely lateral. The ovicell is hyperstomial and recumbent. There is both a 

 zooecial and a zoarial hydrostatic system. 



Historical. The first specimens discovered were confused with Selenaria 

 Busk, 1852, and Lunulites. In 1887 Whitelegge formed the genus Bipora for the 

 species whose apertura were provided with a rimule. In 1910 Maplestone created 

 the family Biporae. Prior to that, in 1900. Xeviani grouped the genera Batopora 

 Reuss, 1847, and Conescharellina D'Orbigny in his family of the Batoporidae, 

 whereas Stichoporina Stoliczka, 1861, and Orbitulipora Stoliczka., 1861, remained in 

 Lepraliidae. Bipora Whitelegge, 1887, was classed in 1895 in Schizoporellidae by 

 MacGillivray. In 1909 Levinsen made a somewhat serious study on the recent 

 genera Bipora Whitelegge, 1887, Conescharellina O'Drbigny, 1851. and Flabellipora 

 D'Orbigny, 1851, and all of the group with rimule of the Biporae; he omitted the 

 recent genus Fedora Jullien, 1882. No author has regarded the family in its en- 

 tirety and the right of priority does not exist. 



This is a very mysterious group, which has given the zoologists much trouble 

 until, in 1910, when Maplestone 1 presented some details on the zoarial life. 



Almost all our specimens belong to a new American genus, Schisorthosecos. 



The zooecial hydrostatic system is analogous to that which we have described 

 for Lunularia Busk, 1884, but with some variations still very imperfectly studied. 

 Around the ancestrula there are some hydrostatic and radicular zooecia and often 

 between the zooecia there are some hydrostatic zooeciules and some zooeciules of 

 reenforcement or compensation. The inner surface of the zoarium being smaller 

 than the external surface, the latter have for their object the making up the dif- 

 ference. 



1 1910. On the Growth' and Habits of Biporae, Proceedings Royal Society Victoria, vol. 23. 



