280 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



The aperture is semilunar or ogival and is surrounded by a prominent peristome; 

 its proximal border is straight with two small lateral slits; there is a vestibular arch. 



[/<a=0.08mm. . fZs=0.44-0.46mm. 



- Zooecia 



I Is =0.20 mm. 

 Breadth of the segments 0.20-0.36 mm. 



Affinities. This species is articulated as in CeUaria; but in its other charac- 

 teristics it is nearer to Macropora. As in that genus, there is a peristome, an oral 

 arch, and two oral slits. We have not seen an ovicell. It" is impossible to estab- 

 lish a new genus on such insufficient material as we possess, since the figured 

 specimens are the only ones which have been found. We dedicate this species to 

 Dr. Frank Burns, who collected many species of Tertiary 

 bryozoa for our study. 



Occurrence. Middle Jacksonian (Castle Hayne limestone) : 

 Wilmington, North Carolina (very rare). 

 Holotype.C&t. No. 64014, U.S.N.M. 



-, P . b . Suborder ASCOPHORA Levinsen, 1909. 



The zooecial hydrostatic system is a sack or compensatrix 

 the Aecophora Levin- 1*0.^ u- v. A u 



sen 1009 placed under the frontal and m which the sea water is Intro- 



Transverse section of a duced. The parietal muscles are attached to this sack. 



zooecium. cs, compen- Trip fO^TTTT AF 



satrix; ect, ectocyst; fp, 



parietal fibers (muscles); (Family CRIBRILINIDAE Hincks, 1880.) 



pi.basal skeleton wall; The zooecia have their f rontal wall formed of flattened 



pf, frontal skeletal wall. 



ribs ordinarily hollow, radiating from the outer border 



toward the median line of the zooecia, where they are intimately joined together; 

 these ribs are united to one another, sometimes by a more or less large number of 

 transverse passages, and sometimes border to border, the ribs, however, always 

 remaining apparent. 



This family is not natural, for its essential characters are too much at variance. 

 We indicate, therefore, the anatomical bibliography for each of the genera studied. 

 In the future, these genera will probably be distributed in the Malacostega and 

 Ascophora. The anatomical researches published have shown the presence of a 

 compensatrix, for which reason we classify the group in the Ascophora; but we 

 recognize that certain genera are unprovided with this organ. 



Terminology. The internal structure of the Costulae has been carefully studied 

 by Norman. 1 The costula (A) (bar of Norman) always has its proximal extremity 

 rounded (fig. 80), forming the loop of Norman or talon of Jullien (C). This 

 structure is hollow ; the hollow part is the lumen line or more simply the lumen. 

 There are often openings in the lumen called lumen pores. The sides of the costules 

 are the lateral lines (D) ; the pore-like openings generally developed between them 



1 1903, Annals and Magazine Natural History, scr. 7, vol. 12, p. 90. 



