98 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



necessary therefore to await more abundant material before the generic position can 

 be determined. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : Wilmington, 

 North Carolina (very rare). 



Holotype.Cnt. No. 63871, U. S N. M. 



MEMBRANIPORINA BENJAMINI Cann and Bassler. 1917. 



Plate 21, fig. 1. 



1917. Membraniporina lenjamini CANU and BASSLER, Synopsis of American Early Tertiary 

 Cheilostome Bryozoa, Bulletin 96, United States National Museum, p. 11, pi. 1, fig. 1. 



Description. The zoarium is incrusting. The zooecia are large, elongate, 

 elliptical, and distinct; the mural rim is rounded, smooth, everywhere of equal 

 width. The opesium is median, elliptical, entire. In the vicinity of the septulae 

 there is often an incomplete small canal. 



. (7^=0.57 mm. 7 . \La= 0.65-0.70 mm. 



BCia |z s =0.4(M).45 mm. 



Affinities. Only the fragment figured, which is of considerable interest, has 

 been found. In the proximal part of the zooecium in front of each septula there is 

 a sort of incompletely calcified tubule, serving probably to protect the mesenchyma- 

 tous filaments which pass from one zooecium to another. 



This interesting species is named after Dr. Marcus Benjamin, the efficient editor 

 of the United States National Museum, to whom we are indebted for many 

 courtesies. 



Occurrence. Middle Jacksonian: Rich Hill, 5} miles southeast of Knoxville, 

 Crawford County, Georgia (very rare). 



Holotype.Cat. No. 62567, U.S.N.M. 



MEMBRANIPORINA TUBULOSA, new species. 



Plate 80, figs. 2-7. 



Description. The zoarium is unilaminar. tubular, and incrusts very small algae. 

 The zooecia are distinct, elongated, hexagonal; the mural rim is level, but little 

 elevated, much enlarged at the base to form a concave cryptocyst. The opesium 

 is anterior, elliptical, entire; the lateral walls bear two small septulae. 



A0=0.20-0.22 mm. . \Lz= 0.40-0.45 mm. 



;Cia Uz=0.30-0.32 mm. 



Affinities. The bifurcation of the zoarium corresponds to that of the alga 

 which served as a substratum. At this bifurcation there is often a giant zooecium. 

 The calcified zooecia have a concave cryptocyst perforated by a large round pore. 

 It appears to us that endozooecial ovicells may be present, but as we are not able 

 to confirm the observation by a dissection it is necessary to await better specimens 

 before placing the species finally. 



