24 BULLETIN 96, UNITED STATES NATIONAL MUSEUM. 



segments, on which the zooecia are arranged in longitudinal rows 

 (generally four to six) around an axis formed by the adjoining sepa- 

 rating walls. (After Levinsen, 1909.) 



There have as yet been no anatomical researches on the representa- 

 tives of the family. 



The known genera are as follows, the last one alone being repre- 

 sented in our American collections. 



Columnaria Levinsen, 1909. Recent. 

 FarciminaHa Busk, 1852. Recent. 

 Nellia Busk, 1852. Lutecian-Recent. 

 We have added Ileterocella Canu 1907, to this famil}'' because it is 

 not yet advisable to create a distinct family for it. 



Genus HETEROCELLA Canu, 1907. 



1907. Heterocella Canu, Bryozoaires ties terrains tertiares dos environs de 

 Paris, Anales de Paleontologie, vol. 2, p. 14. 



The zoarium is articulated with each segment formed of four rows 

 of zooecia. The opesia are alw^ays oblique; they are small on the 

 converging zorocia and large on the diverging ones. On the olocyst 

 at the bottom of the zocecia there are impressions of various forms. 



Genotype. — Vincularia fragilis Defrance, 1820. 



In Europe this genus has been observed only in the French 

 Lutecian. Its constitution is still problematical, for no existing 

 species is comparable to these fossil forms. Some of the zooecia de- 

 scribed by Canu as regenerated are perhaps radicular. In America 

 one new species from the Vicksburgian of Alabama has been dis- 

 covered. 



Family EUCRATIIDAE Hincks, 1880. 



Zoarium forming slender, branching, phytoid tufts. Zooecia 

 uniserial or in two series placed back to back; expanding from the 

 base upwards, with a terminal or subterminal and usually oblique 

 opesium. Neither avicularian nor vibracular appendages known. 

 Ovicell globose hyperstomial. (Robertson.) 

 The genera of this family are: 



Eucratea Lamouroux, 1812, 



Gemellaria Savigny, 1811, 



Scruparia Hincks, 1880, 



Huxleya Dyster, 1858, 



Brettia Dyster, 1858. 



Genus GEMELLARIA Savigny, 1811. 



1811. Gemellaria Savtgny, Icouographie des Zoophytes de I'Egypte. 



Zoarium erect, branching dichotomously, each branch given off 

 from the sides of the zooecia close to their upper extremity. Zooecia 



