NORTH AMERICAN EARLY TERTIARY BRYOZOA. 



195 



We have added Heterocetta Canu, 1007, to this family because it is not yet ad- 

 visable to create a distinct family for it. 



Genus NELLIA Busk, 1852. 



1852. ~S cilia BUSK, Catalogue Marine Polyzoa, British Museum, Cheilostomata, pt. 1, p. IS. 

 The zoaria are jointed. The zooecia are without spinous processes ; the distal 

 wall has at its inner corner a single septula: the ovicells are in almost their whole 



D 



FIG. 51. Geuus Nellia Busk, 1852. 



A-H. Nel/in ociihita Busk, 1852. A, B. Segment, X 20 and a zooecium X 40. (After Smitt, 

 1872.) C. Fragment, X 40. The two proximal zooecia to the left without ovicell. An aviculariau 

 chamber is seen through one of the Literal walls of the middlemost zooecium. D. A zooecium with 

 ovicell, X 75. An imcalcified transverse belt is present. E. A longitudinal section through an 

 ovicell, X 40. F. An avicularium with pit for the insertion of the radical fiber, X 200. (C F, 

 After Lev in sen, 1909.) G, H. Stalk growing from stolon, X 25. The growth is from a spreading 

 stolon from which, at intervals sub-colonies grow, commencing with short calcareous nodes joined 

 by chitinous tubes, X 25. (After Waters, 1913.) nr, avicularia ; ov, ovicell ; op, operculum ; opi, 

 opesia; pr, radicular pore; rd, radical fiber. 



extent immersed into the proximal part of the ordinary zooecium and project only 

 very little on the surface of this. The avicularia are attached by a wide base or 

 partially immersed with calcareous transverse pivot, (After Levinsen, 1909.) 

 12 tentacles. 



Genotype. Nellia oculata Busk. 1852. 



Range. Jacksonian-Recent. 



The genus Nellia of Busk is not the genus Farcimia of Pourtales. The type 

 of the latter, Farcimia cereus Smitt. 1872, requires further examination. 



